Class 8 – Page 2 – PSEB Solutions

PSEB 8th Class Science Solutions Chapter 18 Pollution of Air and Water

October 17, 2024October 16, 2024 by Prasanna

Punjab State Board PSEB 8th Class Science Book Solutions Chapter 18 Pollution of Air and Water Textbook Exercise Questions and Answers.

PSEB Solutions for Class 8 Science Chapter 18 Pollution of Air and Water

PSEB 8th Class Science Guide Pollution of Air and Water Textbook Questions and Answers

Exercises

Question 1.
What are the different ways in which water gets contaminated?
Answer:
There are many different ways in which water gets contaminated such as :

By washing, bathing or other household activities.
By sewage
By toxic chemicals thrown by industries.
By silt.
By garbage and dead bodies dumped in water resources.
By fertilizers, insecticides, pesticides etc.
By deposition of minerals or metals in the river bed.

Question 2.
At an individual level, how can you help reduce air pollution?
Answer:
Steps taken to reduce air pollution at an individual level.

Automobile use is to be reduced and is maintained properly. Unleaded petrol or diesel must be used.
Burning of leaves, tyres etc. must be stopped.
Plant trees or vegetation around the residential areas.
Use of public transport.

Question 3.
Clear, transparent water is always fit for drinking. Comment.
Answer:
It is not a correct statement. Clear, transparent water may appear clean, but it is not pure. It may contain dissolved impurities and many microorganisms. These microorganisms may be carriers of diseases. So, water fit for drinking is clean, clear, transparent, odourless, devoid of germs and dissolved impurities. Best way to get pure water is boiling. Boiling kills the germs and boiled water can be used for drinking purposes.

Question 4.
You are a member of the municipal body of your town. Make a list of measures that would help your town to ensure the supply of clean water to all its residents.
Answer:
List of measures to obtain clean water.

Industrial waste must be treated before throwing into water resources.
Sewage must be treated by physical and chemical methods before dumping in water resources.

Question 5.
Explain the differences between pure air and polluted air.
Answer:
Differences between Pure air and Polluted air.

Pure air	Polluted air
1. The air is clear and transparent.	1. The air is dirty and translucent.
2. No smoke and dust particles can be seen.	2. Smoke and dust particles are in high amounts.
3. No odour is there.	3. It may have foul smell.
4. Microorganisms are absent.	4. Microorganisms are present.

Question 6.
Explain circumstances leading to acid rain. How does acid rain affect us?
Answer:
Acid Rain. When NO₂, N₂O, SO₂ and SO₃ produced from the incomplete combustion of fossil fuels and by smelting of non-ferrous metals combine with water to form HNO₃, H₂SO₃ and H₂SO₄ and fall down in the form of rain, it is called acid rain. It destroys crops, wild plants, steel rail tracks and electrical equipment. It causes irritation of eyes, nose and throat.

Question 7.
Which of the following is not a greenhouse gas?
[а] Carbon dioxide
[b] Sulphur dioxide
[c] Methane
[d] Nitrogen.
Answer:
[d] Nitrogen.

Question 8.
Describe the ‘Green House Effect’ in your own words.
Answer:
Green House Effect. Carbon dioxide is present in the atmosphere in very small proportion. It helps in photosynthesis process. It is also absorbed by oceans to form carbonate rocks. It also produces greenhouse effect. The heating of the earth due to trapped radiations is called greenhouse effect. Our sun emits light consisting of ultraviolet and infrared radiations. Ultraviolet radiations are absorbed by ozone layer, but infrared radiations pass through the atmosphere and reaches the surface of the earth.

Some of the rays are reflected back. The carbon dioxide absorbs these reflected rays. Since infrared radiations have a heating effect, the atmosphere gets heated up. There are four gases which can trap the infrared radiations. These are carbon dioxide (CO₂), water vapour (H₂O), ozone (O₃) and methane (CH₄). Out of these four, carbon dioxide is uniformly distributed in the atmosphere so it contributes mainly towards the greenhouse effect. The name greenhouse is derived from glasshouse in which green plants are kept.

Question 9.
Prepare a brief speech on global warming. You have to make in your class.
Answer:
Global Warming. Global warming as the name suggests is the increase in temperature of the globe i.e. the average temperature of the atmosphere has increased. Few gases like CO₂, methane, ozone are responsible for it.

The quantity of these gases is increasing day by day in the atmosphere. If this is not checked in time, the temperature will have a big rise and there will be hazards all around us. Such as, glaciers will melt, lower area will get submerged in water, rainfall will be affected, sea level will rise affecting production of crops, forests, etc and it will also affect the lifestyle of living organisms. So special and immediate measures are to be taken to stop global warming.

Question 10.
Describe the threat to the beauty of the Taj Mahal.
Answer:
Taj Mahal is one of the seven wonders of the world. It is a white building made up of white marbles. The monument is being threatened by air pollution. The area surrounding Taj is congested with many harmful gases such as Sulphur dioxide, Nitrogen oxides etc.

This is being emitted by burning of fossil fuels by industries established around the Taj. These gases dissolve in rainwater to form acid rain. This acid rain falls on marble, react with it and dissolves and tarnishes it. If no steps are taken to minimise the fall of acid rain, one day marble monument will remain no more and all the marble will get damaged.

Question 11.
Why does the increased level of nutrients in the water? effect the survival of aquatic organisms?
Answer:
With increased quantities of nutrients (nitrates, phosphates etc.) the algae flourish in the water. When this algae die, decomposers decompose it, using oxygen present in water. Thus, there is decrease in oxygen level in water, which affect the survival of aquatic organisms.

PSEB Solutions for Class 8 Science Pollution of Air and Water Important Questions and Answers

Multiple Choice Questions

Question 1.
Ankush noticed that air pollution has increased in the market due to vehicles. Which gas is emitted by vehicles in a large quantity that causes air pollution?
(a) Carbon monoxide
(b) Carbon dioxide
(c) Both (a) and (b)
(d) None of the above.
Answer:
(c) Both (a) and (b).

Question 2.
Which of the following is greenhouse gas?
(a) Carbon dioxide
(b) Carbon monoxide
(c) Oxygen
(d) Hydrogen
Answer:
(a) Carbon dioxide.

Question 3.
The source of air pollution is:
(a) Burning forests
(b) Gas emitted by automobiles
(c) Smoke of burning wood
(d) All of these.
Answer:
(d) All of these.

Question 4.
Which of the gas present in air contains 78%?
(a) Oxygen
(b) Nitrogen
(c) Carbon dioxide
(d) Argon.
Answer:
(b) Nitrogen.

Question 5.
Which fuel is being used in vehicles in big cities like Delhi?
(a) L.P.G.
(b) Biogas
(c) C.N.G.
(d) Natural gas.
Answer:
(c) C.N.G.

Question 6.
Which diseases are caused due to polluted water?
(a) Cholera
(b) Typhoid
(c) Jaundice
(d) All of these
Answer:
(d) All of these.

Question 7.
The cause of diseases related to respiration in children is :
(a) Oxygen
(b) Nitrogen
(c) Water vapour
(d) Smog
Answer:
(d) Smog.

Question 8.
The ordinary chemical method to purify the water is :
(a) Boiling
(b) Filtering
(c) Chlorination
(d) All of the above
Answer:
(c) Chlorination

Question 9.
When was Ganga cleanliness planning started?
(a) In 1965
(b) In 1975
(c) In 1995
(d) In 1985.
Answer:
(d) In 1985.

Question 10.
Which gas reduces the capacity of absorption of oxygen in blood?
(a) Nitrogen
(b) Carbon monoxide
(c) Carbon dioxide
(d) Oxygen.
Answer:
(b) Carbon monoxide

Question 11.
What is the percentage of population which does not get the required water?
(a) 40%
(b) 30%
(c) 25%
(d) 15%
Answer:
(c) 25%

Question 12.
Which of the following is not greenhouse gas?
(a) Carbon dioxide
(b) Sulphur dioxide
(c) Methane
(d) Nitrogen.
Answer:
(d) Nitrogen.

Very Short Answer Type Questions

Question 1.
Who is responsible for deterioration of quality of atmosphere?
Answer:
Man and his activities.

Question 2.
What conditions of environment are lacking these days?
Answer:
Clear sky, fresh air, clean water etc.

Question 3.
What is composition of air?
Answer:
Composition of Air. Air is mixture of gases containing 78% nitrogen, 21% of oxygen and 1% of other gases such as carbon dioxide, carbon monoxide, water vapour, argon, ozone, methane etc.

Question 4.
Which is the main air pollutant?
Answer:
Smoke.

Question 5.
What are the main causes of smoke?
Answer:
Causes of smoke :

Automobiles
Burning of fuels

Question 6.
Name natural air pollutants.
Answer:
Smoke, dust.

Question 7.
Which disease is caused by air pollution?
Answer:
Respiratory problems.

Question 8.
Which gases are released by vehicles?
Answer:
Carbon dioxide, carbon monoxide, nitrogen oxides, smoke etc.

Question 9.
Which gas reduces the capacity of the blood to carry oxygen?
Answer:
Carbon monoxide.

Question 10.
What is smog?
Answer:
Smog. Smog is made up of smoke and fog.

Question 11.
Name some Breathing/Respiratory Problems.
Answer:
Respiratory problems- Asthma, Cough, Wheezing in children etc.

Question 12.
Which chemicals are used in refrigerators, air conditioners, perfumes etc?
Answer:
Chloro-fluoro carbons.

Question 13.
What is ill effect of chloro-fluoro carbons?
Answer:
Chloro-fluoro carbons (CFCs) damage the ozone layer.

Question 14.
Why is ozone layer important?
Answer:
It protects the earth from UV radiation of the sun.

Question 15.
What is the source of suspended solid particles in air?
Answer:
Sources of solid particles in air:

Burning of petrol, diesel in automobiles,
Industrial processes such as steelmaking and mining
Power plants.

Question 16.
What is the effect of suspended particles in air?
Answer:
They reduce the visibility.

Question 17.
Which industries are responsible for acid rain around Taj in Agra?
Answer:
Rubber processing, Automobile, Chemical, Mathura oil refinery.

Question 18.
Which are acid gases?
Answer:
Acid-gases. Sulphur dioxide, Sulphur trioxide, Nitrous oxide.

Question 19.
Name two clean fuels.
Answer:
LPG and CNG.

Question 20.
Which gas has tendency to trap sun radiations and warm the atmosphere?
Answer:
Carbon dioxide.

Question 21.
Name some greenhouse gases.
Answer:
Green House gases. Methane, ozone, water vapours, nitrous oxide, carbon dioxide.

Question 22.
Which protocol has been signed to minimize greenhouse effect?
Answer:
The Kyoto protocol.

Question 23.
Name few alternate fuels.
Answer:
Alternate fuels. Solar energy, Hydropower, Wind energy.

Question 24.
When is Van Mahotsav celebrated in India?
Answer:
In the month of July of every year.

Question 25.
How should dry leaves be disposed?
Answer:
Dry leaves must be put in compost pit to obtain compost.

Question 26.
Which characteristics of water can get changed?
Answer:
Smell, colour and acidity.

Question 27.
Name few water pollutants.
Answer:
Water pollutants. Sewage, toxic chemicals, silt; insecticides, weedicides etc.

Short Answer Type Questions

Question 1.
Give two examples of air pollutants.
Answer:
Examples of air pollutants:

Oxides of Sulphur and Nitrogen.
Radioactive fallout.

Question 2.
What are the major sources of air pollution?
Answer:
The major sources of air pollution are as follows :

Industries. Paper and pulp industries, steel plants, petroleum refineries and chemical plants.
Automobiles
Smoke.

Question 3.
What is sewage?
Answer:
Sewage. The release of huge quantities of municipal and domestic wastes is called sewage. They contain certain organic wastes, toxic substances, which damage biological activities.

Question 4.
Why is the sewage water called polluted water?
Answer:
Sewage water contains human urine and faeces, cloth washings and industrial wastes. This water is totally unfit for drinking, washing and for other purposes. It lacks oxygen. It gives foul smell. It can lead to spread of water-borne diseases. Hence, the sewage water is called polluted water.

Question 5.
How should air pollution be controlled?
Answer:
Steps to control air pollution :

Combustible solid wastes should tie burnt in incinerators.
Automobiles must be either made to eliminate the use of gasoline and diesel oil or complete combustion is obtained in the engine so that harmful products are not emitted.
Excessive and undesirable burning of vegetation should be stopped.

Question 6.
How can pollution of river water be controlled?
Answer:
Pollution of river water can be controlled by :

Mechanical and chemical treatment of sewage at its origin and then allowing the clean, harmless effluents (industrial waste) to flow into the river.
Shifting of present chemical factories and banning the construction of new factories on the river banks.

Question 7.
In what way chloro-fluoro carbons are harmful?
Answer:
Chloro-fluoro carbons deplete the ozone layer in the atmosphere which protects earthly organisms from harmful ultraviolet radiations.

Question 8.
How does carbon monoxide act on humans?
Answer:
Haemoglobin of the blood absorbs carbon monoxide. This in turn reduces oxygen-carrying capacity of blood. The non-availability of sufficient oxygen to the tissues results in death.

Question 9.
Which metals are harmful for health?
Answer:
Lead, Arsenic, Mercury.

Question 10.
Depict the important pollutants of air.
Answer:
Air pollutants.
PSEB 8th Class Science Solutions Chapter 18 Pollution of Air and Water 1

Question 11.
Write the harmful effects of greenhouse effect.
Answer:
Harmful effects of Greenhouse effect. The greenhouse effect will increase the temperature of earth’s surface. It will make the life of men and animals uncomfortable. The scientists have estimated that the sea level will rise by 100 m if the global temperature rises by 3-6°C due to greenhouse effect. If it happens, the coastal regions and many islands will be submerged causing great damage.

Question 12.
Why is Ganga river more polluted at Kanpur?
Answer:
At Kanpur, the amount of water and flow is comparatively less and slow. Near about 5000 industries of Kanpur discharge toxic chemicals into the river. People bath, wash clothes, defecate, throw garbage, flowers, worship material and polythene bags in the river.

Question 13.
How is ozone layer help to us?
Answer:
Ozone layer of atmosphere is very important for all living organisms. It absorbs the harmful ultraviolet rays radiated from the sun which otherwise can give rise to fatal diseases like skin cancer in humans. These rays are also harmful for crops.

Question 14.
Explain the ozone layer.
Answer:
Ozone layer. The ozone gas found in the stratosphere of atmosphere is known as ozone layer. It protects us from ultraviolet rays of the sun. A poisonous substance chlorofluorocarbon is used in refrigerators and air conditioners which attenuates the ozone layer. This is known as depletion of ozone layer.

Question 15.
Which types of problems can arise with an increase in global warming? Write about three problems.
Answer:
Global warming can create following problems.

Summers will become more hot and dry and winters will be damp and colder.
Glaciers will melt down due to increase in global warming and level of sea will rise by two feet.
Water supplies would become disrupted and droughts would be more common.

Question 16.
How the industries located on the bank of Ganga river contribute to pollute it?
Answer:
There ae established industries in very big number in the cities and towns located on the bank of Ganga river. Only in Kanpur, there are more than 5000 industrial units which are adding fertilizers, detergents, poisonous waste of leather and paint industries, sewage, insecticides and garbage etc. in Ganga Paper factories, sugar mills and other chemical factories are polluting the water of Ganga by discharging their wastes in huge amount.

Question 17.
What instructions are issued by government for industries to maintain the cleanliness of holy rivers like Ganga?
Answer:
Oil refineries, textile and sugar mills, paper factories and chemical factories discharging their industries wastes directly into the rivers. As a result, the water of rivers is becoming poisonous. To check it government have passed regulations. According to these regulations, industries are to treat the waste produced for discharging it into water, but quite often the rules are not followed.

Question 18.
How can you help to reduce air pollution. Suggest any two measures.
Answer:
Steps to control air pollution

Combustible solid wastes should be burnt in incinerators.
Automobiles must be either made to eliminate the use of gasoline and diesel oil or complete combustion is obtained in the engine so that harmful products are not emitted.

Question 19.
List sources of noise pollution in your surroundings. Explain how noise pollution is harmful for human beings.
Answer:
Sources of noise pollution :

Sounds of vehicles.
Loudspeakers.
Working Machines.
Bursting of crackers.
Desert coolers.
Radios and televisions at high volumes.
Kitchen appliances.
Hawkers.

Harmful effects of noise pollution :

Lack of sleep.
Hypertension.
Anxiety.
Partial deafness.

Long Answer Type Questions

Question 1.
What steps would you suggest for minimising the air pollution around you?
Answer:
The air pollution can be minimised by the following steps :

Using alternative sources of energy, that are non-polluting such as solar energy, wind energy etc.
Using lead-free fuels, such as Compressed Natural Gas (CNG) for running cars, buses, trucks etc. The vehicles must be regularly checked for pollution.
Setting factories away from residential areas and their chimneys must have filters.
Planting more and more trees, as they purify air.
Not using bags made of plastic, instead using cloth and jute bags.
Recycling materials, such as paper, metal etc.
Avoiding burning of dried leaves, tree branches, paper, garbage etc. as the smoke released causes pollution.
Saving electricity as it would amount to burning of less fossil fuels.
Reducing the use of aerosols (i.e. particles of solid, or liquid matter) that can remain suspended in air from a few minutes to many months depending on particle size and weights, such as perfumes, deodorants etc.
Avoiding smoking and encouraging others also to do the same.

Question 2.
Describe the role of sewage as water pollutant.
Answer:
Sewage can be classified into domestic sewage and industrial wastes. Domestic sewage is one of the most primary sources of water pollution. The industrial wastes also play major role in the pollution of water.
Sewage pollutes rivers, lakes and even oceans. Polluted waters are contaminated with infectious agents for cholera, typhoid, dysentery, jaundice and skin diseases.

In sewage water, there is depletion of oxygen, because the same is required for degradation of sewage. Reduced availability of oxygen causes suffocation and kills many aquatic animals especially fishes. Polluted water becomes unfit for drinking and cooking. The poisonous substances which get dissolved in water, make it unsuitable for aquatic life. It is unfit for agricultural operations also. Scum and sludge get collected and make the water unfit for boating and other recreational purposes.

Question 3.
Write a short note on air pollution.
Answer:
Air Pollution. Air is never found pure due to natural and man-made pollution. An undesirable change in the physical, chemical and biological characteristics of air is called air pollution. The substances which pollute the air are called air pollutants. The common air pollutants are carbon monoxide, carbon dioxide, sulphur dioxide, oxides of nitrogen and suspended particulate matter.

The air pollution is caused by natural processes and human activities. Air pollution has very adverse effects on human beings. It affects raw materials, industrial processes, living conditions and cultural assets like historical monuments. It is posing main dangers to our lives.

Question 4.
Define acidic gases. Give examples. Can you observe its effects on newly constructed buildings made of marble?
Answer:
The gases which combine with water to form acids are called acidic gases.
Example: Sulphur dioxide (SO₂), nitrogen dioxide (NO₂). Effects on buildings made of marble.

The acidic gases (SO₂ and NO₂) react with water present in the air and get converted to acids :
2SO₂ + O₂ + 2H₂O → 2H₂SO₄ Sulphuric acid
4NO₂ + O₂ + 2H₂O → 4HNO₃ Nitric acid

The acids come down to earth with rainwater. The rain containing acids is called acid rain. The acid damages the marble stone (CaCO₃) by dissolving it.
CaCO₃ + H₂SO₄ → CaSO₄ + CO₂↑ + H₂O
CaCO₃ + 2HNO₃ → Ca(NO₃)₂ + CO₂ ↑+ H₂O Marble stone
Therefore, acidic gases damage the buildings made of marble.

Question 5.
Explain ozone depletion.
Answer:
Ozone Depletion:
Ozone layer acts as protector of life on earth. Due to human activities, CFCs produced by man depletes the ozone layer, more ultraviolet radiations reach the surface of earth. It is termed ozone depletion.

Effects of ozone depletion.

UV radiation strikes the earth and these radiations cause skin cancer and damage to eye.
These ultraviolet radiations damage the defence (immune) system of the body.
It may lead to variations in global rainfall.
It causes ecological disturbances such as floods, shortage of food etc.

Question 6.
Describe the sources of water pollution.
Answer:
Sources of water pollution:
PSEB 8th Class Science Solutions Chapter 18 Pollution of Air and Water 2

Following are the sources of water pollution-
1. Domestic effluent. In this case, wastewater is discharged into public sewerage system such as-

Human and animal excreta
Plenty of organic matter in the form of food residue
Detergents
A large number of bacteria.

2. Industrial effluent. Industries usually discharge wastewater into ponds, lakes, and rivers. Industrial wastewater contains heavy metals as mercury, lead, copper, arsenic, and cadmium.

3. Pesticides and fertilizers. The surface water runoff from the field with inorganic fertilizers, pesticides, insecticides, bring heavy loads of pollutants into natural water bodies. Pesticides like DDT are non-biodegradable.

4. Waste Heat. Waste heat is a rise in the temperature of water by human activity. Thermal power plants, refineries, etc. discharge hot water into nearly lakes, sea, etc. The sudden rise in the temperature of the water has very harmful effects on aquatic organisms, such as fish and algae.

PSEB 8th Class Social Science Solutions Chapter 24 Constitution and Law

October 17, 2024October 16, 2024 by Bhagya

Punjab State Board PSEB 8th Class Social Science Book Solutions Civics Chapter 24 Constitution and Law Textbook Exercise Questions and Answers.

PSEB Solutions for Class 8 Social Science Civics Chapter 24 Constitution and Law

SST Guide for Class 8 PSEB Constitution and Law Textbook Questions and Answers

I. Fill in the blanks :

Question 1.
The constitution of India was implemented on ___________
Answer:
26 Jan. 1950

Question 2.
___________ was the first President of India.
Answer:
Dr. Rajendra Prasad

Question 3.
The law against Dowry was enacted in ___________
Answer:
1961 A.D.

Question 4.
The Constitution of India was prepared in ___________ years months and days.
Answer:
2,11,18

Question 5.
The main cause of foeticide is ___________custom.
Answer:
dowry.

II. Put a tick against the Right (✓) and a cross against the wrong (✗) answer:

Question 1.
Gandhiji broke the salt law at Dandi.
Answer:
(✓)

Question 2.
The Judiciary does not protected the constitution.
Answer:
(✗)

Question 3.
The rule of law runs through India.
Answer:
(✓)

Question 4.
To oppose bad laws is the feature of Democracy.
Answer:
(✓)

Question 5.
Laws are Indefinite rules.
Answer:
(✗)

III. Multiple Choice Questions :

Question 1.
When was the Indian Constitution Implement?
(A) Nov. 26, 1949
(B) Jan. 26, 1950
(C) Jan. 26, 1930
(D) Jan. 26, 1949.
Answer:
(B) Jan. 26, 1950.

Question 2.
Who was the Chairman of the constitution draft committee?
(A) Dr. Rajinder Prasad
(B) Dr. B.R. Ambedkar
(C) Mahatma Gandhi
(D) Pandit Jawahar Lai Nehru.
Answer:
(B) Dr. B.R. Ambedkar.

Question 3.
Who is the highest of the following in India?
(A) Prime Minister
(B) President
(C) Judiciary
(D) Constitution.
Answer:
(D) Constitution.

Question 4.
State the number of draft committee members.
(A) 11
(B) 18
(C) 7
(D) 2.
Answer:
(C) 7.

IV. Answer the following questions In not more than 15 words :

Question 1.
What do you mean by Constitution?
Or
Write the meaning of the term Constitution.
Answer:
The Constitution is a legal document through which administration of the country is being run. Central and state governments run their administration according to the Constitution. The Constitution is above of all the laws of the country.

Question 2.
Why was Constitution implemented on 26th January, 1950?
Answer:
Our Constitution was implemented on 26th January, 1950 because of the historical importance of this date. On 26th January, 1930, first independence day of the country was celebrated.

Question 3.
Write the word meaning of Law.
Answer:
Law is an English word. The word “Law’ came out of Tutonic word ‘Lag’ whose meaning is definite. In this way the meaning of law is definite rule.

Question 4.
What is the importance of Law?
Answer:
Law is helpful in maintaining system of any institution or the country. No institution can run in a proper way without the laws. School also has its own laws (rules) with which discipline is maintained in the school.

Question 5.
What do you mean by the impartial Judiciary?
Answer:
The meaning of impartiality of the judiciary is that it works independently without the pressure of executive or legislative. Judiciary in India also has been made impartial. If any institution does not work according to the Constitution, judiciary can declare it unconstitutional.

Question 6.
Which were the movements started by Mahatma Gandhi?
Answer:
Mahatma Gandhiji started Non-Cooperation Movement in 1921, Civil Disobedience Movement in 1930 and Quit India Movement in 1942 A.D.

Question 7.
What do you understand by “Boycott of Liquor”?
Or
What is meant by the prohibition of Liquor?
Answer:
The meaning of Boycott of Liquor is restriction of making whisky by state, sale of whisky and drinking of whisky.

V. Answer the following questions in 50-60 words :

Question 1.
What do you mean by the. supremacy of the Constitution?
Answer:
The Indian Constitution is considered as the highest document.

Persons being appointed in all the important offices of the country are asked to take the oath of the Constitution.
All government and non-government institutions work according to the Constitution.
Judiciary has been made independent and impartial. It has been given a number of rights for the security of the Constitution. Out of these, one right is related to” security and explanation of the Constitution.
A democratic structure has been established in the country according to the Constitution. Citizens are given a number of rights. One of these important rights is the right to criticise the government.

Question 2.
How was the Constitution of India formed?
Answer:
On the 29th of August, 1947, a seven member committee was formed to form the Indian Constitution. This committee studied the Constitutions of many countries. It took 2 years, 11 months and 18 days to complete the Indian Constitution. It was passed by the Constituent Assembly on 29th November, 1949 but was implemented in the country on 26th January, 1950 due to the historical importance of this date.

Question 3.
How has the judiciary been made Impartial in India?
Answer:
Judiciary has been made the independent and unbiased for the security of Constitution. Judiciary determines that the Constitution should be obeyed. If any institution does not work according to the Constitution then it can be declared as unconstitutional. Judiciary has the right to review the laws. It means that if any law made by legislative is against the spirit of the Constitution, it can be dismissed by the Judiciary. In the same way if any work implemented by executive is against the Constitution then it can be declared as unconstitutional.

Question 4.
Why did Gandhi violate the British laws?
Answer:
The British government used to make laws for the country before our independence. The main aim of these laws was to meet the interests of the British government. Indian interests were hardly cared by these laws. For example, British government passed an act in 1919 A.D. called Rowlatt Act according to which government was free to arrest any person just on the basis of doubt. Salt law was also against Indians. It was necessary to break such laws. That’s why Gandhiji broke those laws.

Question 5.
What is meant by prohibition and why should it be put into practice?
Answer:
Meaning of boycotting of liquor is the legal prohibition of making whisky, sale of whisky and drinking of whisky.

Drinking whisky or alcohol is a social evil. According to one survey, every fourth person of the country is alcoholic. Daily 25 crore rupees are being spent on whisky. Not only this it leads to loss of money, loss of health and loss of time. Alcohol takes the person towards moral degradation. That’s why it is necessary to implement the policy of Complete Prohibition.

PSEB 8th Class Social Science Guide Constitution and Law Important Questions and Answers

Multiple Choice Questions :

Question 1.
Indian Constitution was framed by :
(a) Indian Parliament
(b) Dr. Ambedkar British
(c) Constituent Assembly
(d) Parliament.
Answer:
(c) Constituent Assembly.

Question 2.
The Indian Constitution was enforced on :
(a) 9th December 1950
(b) 15th August 1947
(c) 26th Nov. 1949
(d) 26th January, 1950.
Answer:
(d) 26th January, 1950.

Question 3.
Aims of the Constitution are mentioned in the :
(a) Preamble
(b) Fundamental Rights
(c) Directive Principles
(d) None of the above.
Answer:
(a) Preamble

Question 4.
Who was the Chairman of the Drafting Committee of the Constituent Assembly?
(a) Dr. B.R. Ambedkar
(b) Pt. Jawaharlal Nehru
(c) Dr. Rajinder Prasad
(d) K.M. Munshi.
Answer:
(a) Dr. B.R. Ambedkar.

Question 5.
Which of the following right is available under the Indian Constitution?
(a) Right to Equality
(b) Right to Freedom
(c) Right against Exploitation
(d) All the above.
Answer:
(d) All the above.

Question 6.
At present Indian citizen enjoys :
(a) Seven Fundamental Rights
(b) Eight Fundamental Rights
(c) Six Fundamental Rights
(d) None of the above
Answer:
(c) Six Fundamental Rights.

Question 7.
Who was elected as the first president of India?
(a) Dr. Rajendra Prasad
(b) Pt. Jawahar Lai Nehru
(c) Sardar Patel
(d) Mahatma Gandhi.
Answer:
(a) Dr. Rajendra Prasad.

Question 8.
Which of these movements was started by Gandhiji?
(a) Non-Cooperation Movement
(b) Quit India Movement
(c) Civil Disobedience Movement
(d) All of these.
Answer:
(d) All of these.

Question 9.
When was Dowry Prohibition Act passed?
(a) 1960
(b) 1961
(c) 1962
(d) 1963.
Answer:
(b) 1961.

Fill in the Blanks :

Question 1.
Indian Constitution come into force on ___________
Answer:
26 January 1950

Question 2.
___________ was the first President of India.
Answer:
Dr. Rajendra Prasad

Question 3.
Dowry Prohibition Act was passed in A.D.
Answer:
1961

Question 4.
Indian Constitution was made in around ___________ years.
Answer:
Three

Question 5.
Major reason of foeticide is ___________
Answer:
Dowry.

Tick the Right (✓) or Wrong (✗) Answer:

Question 1.
Gandhi Ji broke Salt Law at Dandi.
Answer:
(✓)

Question 2.
Judiciary never protects the country.
Answer:
(✗).

Question 3.
Rule of law is there in India.
Answer:
(✓)

Question 4.
Elimination of wrong laws is a basic aspect of democratic government.
Answer:
(✓)

Question 5.
Laws are indefinite rules.
Answer:
(✗).

Match the Following :

Question 1.

A	B
1. Constitution	(i) Judiciary
2. Protection of Constitution	(ii) 31 Dec. 1929
3. Completion of Constitution	(iii) Legal Document
4. Declaration of Poorna Swaraj	(iv) 26 Nov. 1949

Answer:

A	B
1. Constitution	(iii) Legal Document
2. Protection of Constitution	(i) Judiciary
3. Completion of Constitution	(iv) 26 Nov. 1949
4. Declaration of Poorna Swaraj	(ii) 31 Dec. 1929

Very Short Answer Type Questions

Question 1.
When did India become independent?
Answer:
India became independent on 15th August 1947.

Question 2.
Who framed the Constitution of India? Who was its chairman?
Answer:
The Constitution of India was framed by the Constituent Assembly whose chairman was Dr. Rajendra Prasad.

Question 3.
When was the Drafting Committee of the Constituent Assembly framed? Who was its Chairman?
Answer:
The Drafting Committee of the Constituent Assembly was framed on 29th August 1947. Its chairman was Dr. B.R. Ambedkar.

Question 4.
Who was the first President of India? In which meeting of Constituent Assembly he was elected as President?
Answer:
The first President of India was Dr. Rajendra Prasad. He was elected as the President in the last meeting of Constituent Assembly on 25th January 1950.

Question 5.
Which steps are taken to make Judiciary independent and impartial?
Answer:
Appointment of judges, their salary, perks and term are kept separate from other bureaucrats.

Question 6.
Give two things included in the Civil Disobedience and Non-Cooperation Movements.
Answer:

Not to use things made by the British government.
Not to wear clothes made by them.

Question 7.
Where and how was the salt law broken?
Answer:
Salt law was broken at Dandi (Gujarat) under the leadership of Mahatma Gandhi. Salt made by the British government was destroyed by them and Gandhiji ordered to make salt themselves from the seawater.

Question 8.
Which state governments passed the laws related to complete prohibition? Were they proved fruitful?
Answer:
Complete Prohibition Laws were passed by governments of Gujarat, Haryana, Kerala and Andhra Pradesh. But they were not proved fruitful.

Short Answer Type Questions

Question 1.
Write a note on the formation and implementation of the Constitution of India.
Answer:
After the independence, one Constituent Assembly was formed. Dr. Rajendra Prasad was elected its permanent chairman. This committee was sovereign in its hands.

Formation of Drafting Committee and making of the Constitution. One committee of seven members was formed on 29th August, 1947 to give definite form to the Constitution. It’s chairman was Dr. B.R. Ambedkar. This Drafting Committee studied the Constitutions of different countries and collectecLmany facts from the Constitutions of other countries. Total 11 meetings of the Constituent Assembly were held. The work of making of the Constitution was completed on 26 Nov., 1949. It took 2 years, 11 months and 18 days to make our Constitution. The Constitution was implemented on 26th Jan. 1950. Last meeting of Constituent Assembly took place on 25th Jan. 1950 in which Dr. Rajendra Prasad was elected as the first President, of India.

Question 2.
Why and how Dowry System was banned?
Answer:
The custom of dowry was a curse on our society. This was one of the biggest problems for poor classes right from the ages. Poor people used to take loan to give dowry to their girls. It led to lower status of females in society. That’s why people started to encourage female foeticide. It led to decline in sex-ratio in society. That’s why government was forced to make a law to restrict dowry system and this law was made in 1961. According to this law, giving or taking dowry is an offence.

Question 3.
What do you mean by the Constitution and Law?
Answer:
Constitution. The Constitution is a fundamental and legal document which enjoys the highest place in the country. It is a set of those rules according to which administration of the country is being run. All the government and non-government institutions work according to the Constitution.

Law. Law is that rule which maintains peace and order in the country. Laws are being formed by central and state legislatures. It is necessary for all the citizens of the country to obey the laws of the country. Punishment can be given in case of breaking the laws.

Question 4.
What is the meaning and importance of Law?
Answer:
Meaning. Law is an English word. The word ‘Law’ came out of the Teutonic word ‘Lag” whose meaning is definite. In this way, the meaning of the word ‘Law’ is any definite rule.

Importance of Law: Laws are of great importance in social life. They regulate our social life. Our social life cannot run in a proper way without these laws. For example, if rules (laws) will not be implemented in the school then indiscipline will not prevail in the school. In this way, if criminals will not be controlled by laws then insecurity will prevail in the social life of the society.

Question 5.
List the rights of citizens in a criticism.
Answer:
Rights given to citizens by the Constitution are known as basic rights or fundamental rights. They are six in number and are listed as follows:

Right to Equality.
Right to Freedom.
Right against Exploitation.
Right to Religious Freedom.
Cultural and Educational Rights.
Right to Constitutional Remedies.

PSEB 8th Class Physical Education Solutions Chapter 8 Awareness about Narcotics

October 16, 2024October 15, 2024 by Prasanna

Punjab State Board PSEB 8th Class Physical Education Book Solutions Chapter 8 Awareness about Narcotics Textbook Exercise Questions and Answers.

PSEB Solutions for Class 8 Physical Education Chapter 8 Awareness about Narcotics

Physical Education Guide for Class 8 PSEB Awareness about Narcotics Textbook Questions and Answers

Question 1.
What are the effects of the use of narcotics?
Answer:
Nowadays drugs have become a great problem in our society. The drugs effect the body and mind adversely and ruins the family and social life of the person. Narcotic drugs effect our body systems adversely and cause severe diseases such as blood pressure, diabetes and cancer. The drug-addicted person loses control over his behaviour. Out of anxiety, the person may even Quarrel with his friends and relatives. As a result, his friends and relatives start avoiding him. A drug addict can no more enjoy his social life as he loses his character and is unable to maintain a healthy relation with the members of the society.

Question 2.
What are the reasons of the increasing trends of drug addiction?
Answer:
Students are attracted towards drug abuse due to bad company, movies and songs. Students get inspired by the heroes in the movies picturised as taking drugs because they consider it to be cool, but they are unaware of the fact that drugs can prove to be fatal. Broken marriage or divorce of mother and father can attract their children towards drug addiction. This may, as a result, spoil the family life and may even push the children towards serious drug addiction. Sometimes, parents themselves spoil their children with drugs because they themselves are addicted.

A child spends most of his time with friends and playmates, away from the family members. Therefore, the influence of friends or peer groups is natural. If one of the friends is a drug addict, it will effect the whole group. Sometimes, a case of show-off or boasting may persuade a child to do costly drugs. Due to modem technology and vogue, a child may happen to take drugs.

Question 3.
What are the harmful effects of narcotics?
Answer:
Drugs have become a great problem in the society now a days. Drugs effect the users body by weakening the digestive system, immune system, circulatory system, respiratory system, metabolism, nervous system, etc. The persistent use of drugs may cause many severe diseases such as hypertension, numbness, diabetes, jaundice, cancer, etc. The risk of heart related diseases also increase, hands start shaking, the person suffers mental imbalance as well.

Use of narcotic drugs effects the behaviour of the person very badly. He loses control over his senses and Quarrels with people without any genuine reason. The drug addict remains irritated all the time as the narcotics severely effect all the systems of his body. People of the society avoid him which further adds to his irritation.

Question 4.
What are the measures to get rid of drug addiction?
Answer:
It is very difficult to make a person Quit using drugs. However, addicted person must be prepared mently and physically, to give up narcotics by the following manner:

1. Motivation:
The school teachers, parents, friends and team mates play an important role to motivate the children to avoid narcotics. They should aware the person of the ill effects of narcotics. Only friendly and sympathetical behaviour can work well in these cases. He can prepare himself to give up drugs with the counselling of the psychologist.

2. Yog Asana:
Yog Asanas play an important role to motivate the addicted person to avoid using drugs as yoga is a gift from the Indian culture. Now-a-days popular all over the world, yoga is very useful to relieve mental and physical stress. The Asanas are very good to prevent the mental and physical diseases and drug addiction as well.

3. Role of family:
The role of family plays an important role to make the person drug-free. Drug addicted person must be treated with love and affection. In this way, needful corporation from his family, friend and relatives can help the person Quit the abuse of drugs.

4. Sports Entertainment:
Sports help the children to be physically and mentally fit and make best use of free time. In this way the attention gets diverted from the bad company and the children may be free from bad habits like drug addiction.

5. Organising Seminars:
It is very needful that the school and colleges should organise seminars on the harmful effects of the drugs abuse. They should make the students aware about the harmful effects of smoking, drinking alcohol, doing other harmfuL drugs, etc. In these seminars, experts should be invited to spread awareness.

6. Family Attitude:
Parents and teachers should have sympathetic and friendly attitude towards the children. So they may share the problems and feelings with their parents and teachers. In this way, they can keep the children away from drug addiction.

PSEB 8th Class Physical Education Guide Awareness about Narcotics Important Questions and Answers

Multiple Choice Questions

Question 1.
Mention the bad effects of drug:
(A) Men become very weak.
(B) Fall victms to many diseases.
(C) Digestive and Muscular system become weak.
(D) Above all.
Answers:
(A) Men become very weak.
(B) Fall victms to many diseases.
(C) Digestive and Muscular system become weak.
(D) Above all.

Question 2.
Write the causes of increasing intoxicants:
(A) Social causes
(B) Effects of technology
(C) Family causes
(D) Above all.
Answers:
(D) Above all.

Question 3.
Mention ways to prevent intoxicants:
(A) Prerena
(B) To organise seminar.
(C) Psychological effect
(D) Above all.
Answers:
(A) Prerena
(B) To organise seminar.
(C) Psychological effect

Question 4.
Name any four drugs:
(A) Wine
(B) Tabacco
(C) Afeem and Ganja
(D) Above all.
Answers:
(D) Above all.

Very Short Answer Type Questions

Question 1.
What are narcotics?
Answer:
Narcotics are the drugs which make a person lose his mental and physical balance.

Question 2.
Write the changes in a person after taking narcotic drugs.
Answer:
There are many kinds of changes that can be seen like ill-behaviour and lose in senses.

Question 3.
Write the effects of using narcotic drugs.
Answer:
The drugs effect the social & economic status of the person. The abuse of drugs also spoils his family life because the person may cheat the trust of the family members.

Question 4.
Write any two effects of narcotic abuse.
Answer:

Unhealthy social life.
Breaking of relations with family and relatives.

Question 5.
Write any two harmful effects of narcotics.
Answer:

Effects the numerous systems of the body.
Adverse effects on behaviour.

Question 6.
Write any two measures to get rid of drug addiction..
Answer:
1. Motivation: The parents, school teachers and elders of the family play an important role to motivate the children to avoid narcotics.

2. Psychological Method: If it seems difficult, then the person should be prepared to give up drugs with the counselling of a psychologist.

Short Answer Type Questions

Question 1.
What are Narcotics?
Answer:
Narcotics are the drugs which spoil the life of the user and the person becomes isolated. He gets ignored by his relatives.

Question 2.
Write the reasons of increasing trend of drug addictions.
Answer:
1. Sometime children start comparing their economic life with that of their friends. Therefore, they try to boast by taking costly drugs.
2. Effect of Technology: Technology has made our life very comfortable. The child gets attracted to the drugs available on the internet and thereafter starts abusing them.

Question 3.
Write the bad effects of drugs.
Answer:
The drugs effect the body and mind of the user. Nobody wants his friendship and he loses his character and the relationship with the society becomes unhealthy.

Question 4.
Write the effects of harmful narcotics.
Answer:

The use of drugs cannot compete the role of society and rules of the games.
By hook or by crook the person intends to maintain his own status in the society and in the playing ground.

Question 5.
What is the harmful effect of narcotics?
Answer:
Narcotic drugs weaken the human body and effects the mind also. The behaviour of the person seems out of control. This effects his personal and social life.

PSEB 8th Class Physical Education Solutions Chapter 7 Yoga

October 16, 2024October 15, 2024 by Prasanna

Punjab State Board PSEB 8th Class Physical Education Book Solutions Chapter 7 Yoga Textbook Exercise Questions and Answers.

PSEB Solutions for Class 8 Physical Education Chapter 7 Yoga

Physical Education Guide for Class 8 PSEB Yoga Textbook Questions and Answers

Question 1.
What is the philosophy of yoga?
Answer:
Philosophy of yoga is based on the soul of a person who is a part of God himself. Today man has forgotten God and as a result he has lost his actual power gifted to him by God. That is why he is not able to do his duties well. As a result of it he fails in every walk of life and his mind gets distracted. He is unable to solve his problem and feels weak physically, mentally, spiritually and emotionally. So his life becomes full of worries and sorrows.

The philosophy of yoga shows the right path to the people. Yoga always motivates to follow non violence. We should not be the “diverted” human beings. Yoga philosophy accepts ‘non-violence’ as a big religion.

Question 2.
What do you know about the goal of yoga?
Answer:
Goal of yoga is to connect one’s soul to God by strengthening him physically, mentally, emotionally and spiritually. In other words, it is the liberation of the soul from worldly suffering or problems. Yoga prepares a person to face all the problems of life with determination so that he may not distract from his path.

Question 3.
What are the objectives of yoga education?
Answer:
1. To achieve higher level of consciousness:
Through meditation and other spiritual practices our soul can be connected to the eternal power. In this way, by elevating the consciousness to higher level, an individual gets enlightenment.

2. To infuse moral values:
Yoga asanas helps the person to meditate and as a result of meditation, person feels inner calm and peace which leads to religious faith, values, ethics, principles and morals.

3. To achieve emotional stability:
Yoga exercise makes the person capable of overcoming one’s emotions. Hence it helps in maintaining balance of mind. Therefore, yoga has been proved as a boon to the worried and stressed people. Yoga relaxes them and makes them able to control their emotions in the critical conditions so that they can lead a happy and contented life.

4. To achieve good health:
Yoga asanas are like physical exercises but when performed properly and regularly one’s body becomes strong, healthy and fit. Different asanas work very well to keep the different organs of the body fit and healthy because it increases the immunity of the body.

5. To achieve mental strength:
Yoga exercises not only strengthen a person physically but it makes him meditate so that his mind becomes stable and the person becomes mentally strong. It develops self confidence and because of self confidence he does not lose his heart even in the most difficult situations. He faces them bravely and becomes capable to solve the entire problem in no time.

Question 4.
What do you know about Ashtang yoga?
Answer:
Ashtang Yoga has 8 components and therefore it is called “Ashtang”.
According to Rishi PatanjaU, there are eight stages or components of Yoga. They are as follows-

Yama (Forbearance)
Niyama (Observance)
Asana (Posture)
Pranayama (Regulation of breathing)
Pratyahara (Abstraction)
Dharana (Concentration)
Dhyana (Meditation)
Samadhi (Trance)

The first five components or stages out of the above-mentioned eight stages are connected with external Yogic exercises, and the remaining three are related to internal Yogic exercises. All these stages have been further divided as follows:

1. Yama (Forbearance):
It has the following five components-

Ahimsa (Non-violence)
Satya (Truth)
Astey (Conquest of the senses of mind) id) Aprigraha (Non-receiving)
Brahmacharya (Celibacy).

2. Niyama (Observance):
This, too has the following five stages or components-

Shauch (Obeying the call of nature)
Tapa (Penance)
Santosh (Contentment)
Savadhyaye (Self-study)
Ishwar Paridhan (God-consciousness).

3. Asana (Posture):
The number of Asana is as much as the number of birds. Asanas should be performed according to the capacity of the body. They should be done -by exhaling air through breathing, stopping breath and re-breathing.

4. Pranayama (Regulation of breathing):
Pranayama is a part of meditation. It has the following three parts-

Purak (Inhalation)
Rechak (Exhalation)
Kumbhak (Holding of Breath). Holding breath and exhalation are called Pranayama (Regulation of breathing).

5. Pratyahara (Abstraction): Pratyahara means detachment of mind from all the worldly pleasures and comforts.

6. Dharana (Concentration): Dharana means exercising control over our organs. But it is very difficult to practise it.

7. Dhyana (Meditation):
When a person gains control over mind the state of dhyana sets in this state, body and mind become like the flow of the river in which the currents of water have no effect at all.

8. Samadhi (Trance):
It is the state of mind which starts with dharana, dhyana and finally samadhi. All these states have deep connection among them.

The science of yoga is a valuable contribution of India to the world. Yoga is gaining popularity at home and abroad. All the doctors and teachers of physical education acknowledge its utility. Yoga exercises are completely scientific in nature and in accordance with the stucture of the body.

PSEB 8th Class Physical Education Guide Yoga Important Questions and Answers

Multiple Choice Questions

Question 1.
What is yoga?
(A) Aided
(B) To meet God with Atama
(C) Ahimsa
(D) Above all.
Answers:
(A) Aided
(B) To meet God with Atama
(C) Ahimsa

Question 2.
Objective of Yoga:
(A) Control on Emotion
(B) Healthful living
(C) Mentally strong
(D) All above.
Answers:
(D) All above.

Question 3.
How many parts are there in Ashtang Yoga?
(A) Four
(B) Six
(C) Seven
(D) Eight.
Answers:
(D) Eight.

Very Short Answer Type Questions

Question I.
When should we take bath after doing asana?
Answer:
After half an hour.

Question 2.
What type of floor is required to perform asana?
Answer:
Levelled floor.

Question 3.
What type of dress should we put on while doing asanas?
Answer:
Dress should be loose and minimum.

Question 4.
What asana should be done to remove Constipation?
Answer:
We should do the Tar and Sarvang asana.

Question 5.
What asana should be done to remove obesity?
Answer:
Hal asana and Dhanur asana.

Question 6.
Which asana should be done to remove obesity and abdominal disease?
Answer:
Pashchimotan and Bhujang asana should be done to remove obesity and abdominal disease.

Question 7.
Which is the oldest method of Indian exercises?
Answer:
Yoga Asana.

Question 8.
How much time Sheersh Asana may be performed daily?
Answer:
2 minutes only.

Question 9.
Name the asana which prevents Hernia and Urinary diseases.
Answer:
Chakra Asana.

Question 10.
Mention any two advantages of Sheersh Asana.
Answer:

Increases the learning power.
Removes the fat of the body.

Question 11.
Mention any two advantages of Vazur Asana.
Answer:

It cures night fall.
It also cures diabetes.

Question 12.
Mention any two advantages of Padam Asana.
Answer:

Cures the pain of waist.
Passing out of urine becomes normal.

Question 13.
Describe any two advantages of Bhvijang Asana.
Answer:

Removes constipation.
Albumin disease is cured.

Question 14.
Mention any two advantages of Dhanur Asana.
Answer:

Arthritis is cured.
Menstruation and Venereal diseases of women are cured.

Question 15.
Which is the means of uniting soul with God?
Answer:
Yoga.

Question 16.
Which is the best asana for mental concentration?
Answer:
Padam Asana.

Short Answer Type Questions

Question 1.
“Yoga is the means of uniting soul with God.” How? Or What is yoga?
Answer:
“Yoga can be defined as science of healthy and better living physically, mentally, intellectually and spiritually.” Thus, Yoga is the union of soul with God. The medium of this sweet and happy union is body. The union of soul and God takes place by means of healthy and strong body, and we can have a vision of the Almighty God. Yoga makes body strong and healthy. As such, it is the only means of the union of soul and God.

God is the embodiment of other-worldly qualities, actions and knowledge. He is all pervading like the sky. The mutual relation between the living being and God is a must. Yoga is helpful in strengthening these bonds or connections. Man’s aim is to enjoy all the comforts of the world and to make the living soul one with God so that he may get rid of the cycles of births and rebirths and attain salvation.

Question 2.
Yoga is becoming very popular in foreign countries. Why?
Answer:
Yoga is an ancient knowledge of India. Yogic science is very important in human life. All over the world doctors and physical education teachers accept the importance of this ancient knowledge. Yoga Asanas are based on scientific knowledge and useful for persons of all ages. Yoga contributes in the complete development of man.

Question 3.
Write any five points which one should bear in mind while doing Asanas.
Answer:
1. Yoga Asanas should be performed in the morning after the practitioner eases himself. It is better to perform Yoga Asanas after having a bath. After taking bath body feels light and flexible and Asanas get performed very easily. Asanas can, of course, be done on empty stomach in the evening, too.

2. The place of Asanas should be clean and peaceful. It is desirable if Asanas are performed in a green park or garden.

3. The place where Asanas are to be performed should be even. Asanas should be performed on a mat so that one’s concentration is not disturbed by gravitational pull of the earth or by anything else.

4. One should not indulge in talks while performing Asanas. One should concentrate on one’s breathing and on the organ on which pressure is felt. The more one gets concentrated the more shall Be the benefit of the Asanas performed. Perform Shavasana before doing other Asanas to make body, mind and breath calm and poised.

5. Yogic exercises are slow and non-aggressive. They should never be performed with jerks. Each Asana should be performed slowly by making the body alert and tense. Then the body should be kept in a relaxed state after some time. The second Asana should be performed when breathing becomes normal.

Question 4.
What is the importance of Shav Asana?
Answer:
This asana should be performed for 3-5 minutes. It should be performed at the start and end of every asana.
Importance:

Shavasana helps in getting rid of high blood pressure and mental tension.
It keeps the heart and the brain fresh.
It removes the fatigue of the body.

Question 5.
Describe the advantages of Yoga Asanas.
Answer:
1. Man’s basic faculties of body and mind develop by means of Yoga. Lungs get enough air through the exercise of pranayama, as a result of which they get exercised and energised, and get rid of many ailments.

2. Man’s body remains completely healthy through Yoga. Dhoti and Basti help in cleaning liver and intestines respectively. Clean body, we know, always remains healthy.

3. Body gets strengthened with Yoga.

4. By doing Yogic Asanas the organs of body become flexible. For example, Hal-Asana and Dhanush-Asana help in increasing the flexibility of the backbone.

5. All body systems begin to function properly with Yogic exercises.

6. Yogic exercises keep human body in good and correct posture, as a result of which man’s personality improves. For example, by doing Brikh-Asana, knees do not strike, and by doing Padam-Asana”, one’s belly does not protrude and shoulders do not develop hump.

7. Mental discipline develops by doing Yoga. By doing Yama and Niyanfa, one is enabled to exercise control on one’s undesirable emotions and vices.

8. Many ailments get removed by performing Yoga Asanas correctly. Vajar-Asana and Mastainder-Asana help in the removal of diabetes. Similarly, Pranayama keeps the lungs free from ailments.

9. Yoga Asanas help in removing physical and mental fatigue. Shavasana helps in the removal of tiredness.

10. Man’s intelligence and memory increase as a result of performing Yoga Asanas. Shirash-Asana proves to be very useful in this respect.

11. Yogic exercises develop a sort of rhythm in man’s body.

12. Yogic Asanas are the best means of attaining peace and balance of mind.

Question 6.
Describe the Technique of Shav Asana.
Answer:
Shav Asana. In this asana, one lies down prostrate and loosens the body. In order to perform this asana, lie down straight on the ground over the back and loosen all the parts of the body completely. Gradually, breathe in deeply. The distance between the feet should be 1.5 ft.
PSEB 8th Class Physical Education Solutions Chapter 7 Yoga 1
Keep the wrists of the hands away from the body, facing the sky. Close your eyes, introspect and think as if the body were getting loose. Feel that the body is in a position of rest.

Question 7.
Which asanas are useful for reducing Fatness/Obesity and the trouble of the stomach?
Answer:

Tar Asana
Shirsh Asana
Padam Asana
Paschimotan Asana
Bhujang Asana
Chakra Asana
Dhanush Asana.

PSEB 8th Class Agriculture Solutions Chapter 8 Organic Farming

October 16, 2024October 15, 2024 by Prasanna

Punjab State Board PSEB 8th Class Agriculture Book Solutions Chapter 8 Organic Farming Textbook Exercise Questions and Answers.

PSEB Solutions for Class 8 Agriculture Chapter 8 Organic Farming

Agriculture Guide for Class 8 PSEB Organic Farming Textbook Questions and Answers

(A) Answer in One to Two words:

Question 1.
According to the organic farming concept should we feed the soil or plant?
Answer:
Feed the soil, not the plant.

Question 2.
Where is National Centre for Organic Fanning situated?
Answer:
In Ghaziabad.

Question 3.
Shallow rooted crops should be rotated with which type of crops?
Answer:
Deep rooted crops.

Question 4.
Is burning of crop residues allowed or not in organic fanning?
Answer:
Burning of crop residue is not allowed.

Question 5.
Can Bt crops be grown in organic fanning?
Answer:
No, Bt crops can not be grown.

Question 6.
Which types of crops are grown as intercrops in organic fanning?
Answer:
Leguminous crops.

Question 7.
Name any one bio-fungicide.
Answer:
Trichoderma.

Question 8.
Name any one bio-insecticide.
Answer:
At trichogramma.

Question 9.
Name the website from where information on organic farming can be obtained.
Answer:
www.apeda.gov.in.

Question 10.
In which year India formulated standards for organic farming?
Answer:
In year 2004.

(B) Answer in One to Two sentences:

Question 1.
Which type of crops should be rotated in field under organic farming?
Answer:
Rotate deep roots crops with shallow rooted crops and legumes with non legumes.

Question 2.
What are the causes of increasing demand of organic products?
Answer:
People have become aware about the adverse effects of modem agricultural practices. Purchasing capacity of the people have also increased. This has led to the increasing demand for organic food products.

Question 3.
Which countries are die major markets for organic products?
Answer:
Countries which are major markets for organic products are America, Japan and European union.

Question 4.
Define organic fanning.
Answer:
Organic farming is a system of farming in which agricultural production is done without harming or damaging natural resources like soil, water and air and also without using chemical fertilizers, herbicides, fungicides and insecticides.

Question 5.
Define organic standards.
Answer:
Organic standards are certain minimum requirements which must be met for organic food production. In India these standards were formulated in year 2004. Which are acceptable by other countries.

Question 6.
Which areas in India are more suitable for organic fanning?
Answer:
Areas which are organic by default or are nearly organic and where rainfall is 68%, organic farming should be promoted in such areas.

Question 7.
Which organic products have higher demand in world food market?
Answer:
There is a huge demand of tea, basmati rice, vegetables, fruits, pulses etc. which are grown by adopting organic farming practices, in the world organic food market.

Question 8.
Which countries have higher demand for organic products?
Answer:
Organic products are in higher demand in countries like, Japan, America, European Union.

Question 9.
What are the organic standards for use of seed in organic fanning?
Answer:
Seed should be taken from organic crop but if such seeds are not available then use untreated conventional seeds.

Question 10.
How weeds can be managed in organic maize?
Answer:
Cow pea is sown in maize rows as inter crop and it is harvested after 35-40 days of sowing. This practice controls weeds in maize and green fodder is also obtained.

Question 1.
Why there is need to go in for organic farming?
Answer:
Our country became self-sufficient in grains due to green revolution. But excessive use of fertilizers, pesticides, fungicides etc. have deteriorated natural resources like soil, air and water to large extent. Due to adopting wheat-rice crop cycle for many years, area under traditional crops like pulses and oil seed crops have decreased.

We forgot the basic principle of rotation of shallow rooted crop with deep rooted crops and of N legumes with non-legumes. Unnecessarily and untimely application of urea reached deep into the soil with the rain water. Pesticide residues have appeared in food products, milk etc. People have become aware about the adverse effects of modem agricultural practices. Purchasing capacity of the people have also increased. This has led to the increasing demand for organic products. To meet this demand organic farming is in need.

Question 2.
How soil fertility is maintained under organic farming?
Answer:
In organic farming, agricultural production is done by maintaining natural balance and without harming natural resources. Soil fertility is maintained by doing following things:

Chemical fertilizers, pesticides, fungicides are completely prohibited.
Cultivation of leguminous crops is must in the crop rotation cycle.
Burning of crop residue is not allowed.
Contaminated water like sewage water can not be used for irrigation.
Use beneficial insects and birds for protecting crops against insects and pests.
Genetically modified crops are not allowed.

Question 3.
How insect-pests and diseases are controlled in organic farming?
Answer:
In organic farming chemical fertilizers, insecticides, fungicides etc. are totally prohibited. In this practice insects and diseases are controlled by natural methods. Beneficial insects and birds are used for controlling , pests and insects. Extract of neem and bio-pesticides (Bt trichogramma) are used to control pests and insects. Bio fungicides like trichoderma etc.can be used for disease management. Mixed cropping like wheat and ’ gram help in fighting against diseases and insects and pests.

Question 4.
What is organic certification and who does provide the certification?
Answer:
If organic products are to be sold in market or if these are to be exported to other countries then organic certification is must. Certification guarantees that the organic product is produced as per the organic standards. Government of India has authorized 24 certification agencies.

A farmer has to register his farm with any one of the agencies. Inspectors of the agency visit the farms and check the compliance of organic standards by the farmer. After satisfaction, agency certifies the produce as organic. One can get more information about organic standards and certification at the site www.apeda.gov. in.

Question 5.
What are the advantages of organic farming?
Answer:
Advantages of organic farming are:

Fertility of the soil increases.
Production cost is reduced.
Organic produce is sold at higher price.
This is sustainable agricultural practice.
It helps in increasing employment.
Poisonous residue is not found in environment and food items.

PSEB 8th Class Agriculture Guide Organic Farming Important Questions and Answers

Very Short Answer Type Questions

Question 1.
How is hoeing done in organic farming?
Answer:
Manually by hands, wheel hoe or by tractor.

Question 2.
Which crops are sown as inter crops in organic farming.
Answer:
Legumes.

Question 3.
To meet nutritional requirement of crops in organic farming which non-edible cake is used?
Answer:
Castor cake.

Question 4.
How many certification agencies have been authorized to do organic certification in India?
Answer:
24 agencies

Question 5.
How much food grains are required by 2020?
Answer:
276 million ton food grains.

Short Answer Type Questions

Question 1.
Give two advantages of organic farming.
Answer:

Fertility of the soil is maintained and is increased.
More income from organic produce.

Question 2.
Cultivation of which crops is reduced due to green revolution.
Answer:
Area under the cultivation of the traditional crops like pulses and oil seed crops is reduced due to wheat rice crop cycle which helped in bringing green revolution.

Question 3.
Which organic produce is in demand in world market and which countries provide market for these products?
Answer:
Basmati rice, vegetables, fruits, tea, pulses and cotton are in demand in Japan, America and European Union.

Long Answer Type Question

Question 1.
Write a note on production of organic crops.
Answer:
Agricultural practices to be followed for the production of organic crops are the same as for conventional crops e.g. seeds, varieties, method, of sowing etc. In organic farming chemicals like, pesticides, weedicides, fungicides etc. are prohibited. Weed control management is done by crop rotation or by some agricultural methods.

In maize rows cowpea is sown which helps in controlling weeds and also provide green fodder. In turmeric fields rice straw mulching is done to control weeds. Legumes help in maintaining the fertility of the soil by fixing nitrogen of the atmosphere in the soil. Nutritional requirements of the crops are met with by using farm yard manure, compost, vermicompost etc. Insects and pests are controlled by beneficial insects and birds and also by using biopesticides like, extract v of neem. Mixed farming system also helps in managing insects and diseases.

PSEB 8th Class Science Solutions Chapter 15 Some Natural Phenomena

October 16, 2024October 15, 2024 by Prasanna

Punjab State Board PSEB 8th Class Science Book Solutions Chapter 15 Some Natural Phenomena Textbook Exercise Questions and Answers.

PSEB Solutions for Class 8 Science Chapter 15 Some Natural Phenomena

PSEB 8th Class Science Guide Some Natural Phenomena Textbook Questions and Answers

Exercises

Select the correct option in Questions 1 and 2.

Question 1.
Which of following cannot be charged easily by friction?
(a) A plastic scale
(b) A copper rod
(c) An inflated balloon
(d) A woollen cloth.
Answer:
(b) A copper rod.

Question 2.
When a glass rod is rubbed with a piece of silk cloth the rod
(а) and cloth both acquire positive charge.
(b) becomes positively charged while the cloth has a negative charge.
(c) and the cloth both acquire negative charge.
(d) becomes negatively charged while the cloth is positive charged.
Answer:
(b) becomes positively charged while the cloth has a negative charge.

Question 3.
Write T against true and F against false in the following statements.
[а] like charges attract each other.
Answer:
False

[b] A charged glass rod attracts a charged plastic straw.
Answer:
True

[c] Lightning conductor cannot protect a building from lightning.
Answer:
False

[d] Earthquakes can be predicted in advance.
Answer:
False

Question 4.
Sometimes, a crackling sound is heard while taking off sweater during winters. Explain.
Answer:
Woollen clothes get electrically charged when they get rubbed. Due to rubbing attraction or repulsion occurs between their loose particles which results in crackling sound.

Question 5.
Explain why a charged body loses its charge if we touch it with our hand.
Answer:
Human body is a conductor of electricity. When a body is touched with hand, the electric current of body passes to the earth through human body and body loses its charges.

Question 6.
Name the scale on which the destructive energy of an earthquakes is measured. An earthquake measures 3 on this scale. Would it be recorded by a seismograph ? Is it likely to cause much damage ?
Answer:
Scale used to measure earthquake is Richter scale.
Earthquake with measure 3 can be recorded on seismograph but this earthquake is very feeble in its intensity and very less destructive.

Question 7.
Suggest three measures to protect ourselves from Lightning.
Or
Suggest any two safety measures that we should take to prevent damage caused by linghtning.
Answer:
Measures of Protection:

On hearing thunder, go inside closed areas such as houses, buildings etc.
In bus, close all the doors and windows.
In open, sit on floor with your head in knees and arms.

Question 8.
Explain why a charged balloon is repelled by an other charged balloon whereas an uncharged balloon is attracted by another charged balloon ?
Answer:
Same materials get same charges on rubbing and same charges repel each other.
Therefore, balloon on rubbing are similarly charged and thus repel each other while a charged and an uncharged balloon attract each other.

Question 9.
Describe with the help of a diagram an instrument which can be used to detect a charged body.
Answer:
PSEB 8th Class Science Solutions Chapter 15 Some Natural Phenomena 1
Electroscope is used to detect electric charges or kind of charge on a body.
To make an electroscope, take a glass jar. Cover it with a wooden or cardboard disc fixed with an aluminium foil on a paper clip in the vertical position.

Question 10.
List three states in India where earthquake are more likely to strike.
Answer:
States of India, highly susceptible to earthquake:

Rann of Kutch
Rajasthan
Highlands of Sind-Ganga
Kashmir.

Question 11.
Suppose you are outside your home and an earthquake strikes. What precaution would you take to protect yourself ?
Answer:
Protection against earthquake outside the house.

Lie down in open far from buildings, trees and electric wires.
Do not step out from car or bus.
Take car or bus towards open areas.

Question 12.
The weather department has predicted that a thunderstorm is likely to occur on a certain day. Suppose you have to go out on that day. Would you carry an umbrella ? Explain.
Answer:
To go out during thunderstorm is not safe and with umbrella it is fatal because high buildings, electric wires, black materials etc. all attract thunderstorm. So, it is advisable to stay away from them.

PSEB Solutions for Class 8 Science Some Natural Phenomena Important Questions and Answers

Multiple Choice Questions

Question 1.
How many kinds of electric charge are there ?
(a) 2
(b) 3
(c) 4
(d) 6.
Answer:
(a) 2.

Question 2.
The device used for testing electric charge is called:
(a) Electroscope
(b) Microscope
(c) Periscope
(d) Electroplating.
Answer:
(a) Electroscope.

Question 3.
What is the measure of earthquake on Rictor scale that can cause devastation ?
(a) Less than 5
(b) Between 5 and 7
(c) Between 1 and 5
(d) More than 7.
Answer:
(d) More than 7.

Question 4.
Opposite charges ………………. each other.
(а) Attract
(b) Repel
(c) Sometime attract sometime repel
(d) Neither attract nor repel.
Answer:
(a) Attract.

Question 5.
The central region of earth is called:
(a) Inner core
(b) Outer core
(c) Mantle
(d) Earth crust.
Answer:
(a) Inner core.

Question 6.
Which is the safest place to take shelter during lightning and thunderstorm ?
(a) Building
(b) Open area
(c) Under the tree
(d) All the above.
Answer:
(a) Building.

Very Short Answer Type Questions

Question 1.
What is amber ?
Answer:
It is a type of resin.

Question 2.
What happens when amber is rubbed for longer time ?
Answer:
A spark is produced.

Question 3.
Who established that spark and lightning were same thing ?
Answer:
Benjamin Franklin, an American Scientist.

Question 4.
What happens when a plastic scale rubbed with dry hair is brought near pieces of paper ?
Answer:
Scale attracts pieces of paper.

Question 5.
Give few examples of charged objects.
Answer:

Plastic scale rubbed with hair.
Plastic refill rubbed with polythene.
Balloon rubbed with woollen cloth.

Question 6.
What happens when two balloons rubbed with woolen cloth are brought together.
Answer:
They repel each other.

Question 7.
Which type of charges attract each other ?
Answer:
Unlike or opposite charges attract each other.

Question 8.
How many types of charges are there ?
Answer:
Two types of charges-

negative and
positive.

Question 9.
Why does a plastic comb rubbed in hair attract small bits of paper ?
Answer:
Because it gets charged.

Question 10.
What will happen when two clouds with unlike charges approach each other ?
Answer:
Lightning strikes.

Question 11.
Is human body a conductor or an insulator ?
Answer:
A conductor.

Short Answer Type Questions

Question 1.
Why is a balloon filled with air rubbed against hair, sticks to the wall when pressed against it ?
Answer:
Air filled balloon when rubbed against hair gets, charged. The charged balloon then sticks to the wall, when pressed against it. It is because the charged balloon attracts the wall and holds on to it.

Question 2.
Why does the paper strip open up when touched with a charged rod ?
Answer:
When we touch one side of the paper strip with a charged rod, the paper strip opens up. The reason for this is that the two sides of the strip get same type of charge from the charged rod and thus repel each other. With the result, the paper strip opens up (diverges).

Question 3.
Why are we advised not to be under a tree, if we are in the open during a thunderstorm ?
Answer:
A highly charged cloud when comes near the tree can induce a powerful opposite charge on the top of tree. This can cause lightning between the cloud and the earth through the tree. It can damage tree and can cause fire.

Question 4.
Why are tall buildings provided with metallic rods, running from the top of building to the ground ?
Answer:
A highly charged cloud can induce an opposite charge on the pointed ends of the metallic rod. When it passes by the tall building, the similar charge passes to the earth through the metallic rod. The lightning passes to the earth safely, without causing any damage to the building.

Question 5.
What do you mean when we say that a body is electrically charged or electrified ?
Answer:
A body like plastic comb, pen, etc. when rubbed with another body gets the property of attracting small pieces of paper or a pith ball. Then, such a body is a called electrically charged or electrified.

Question 6.
Write a short note on Tsunami.
Answer:
Tsunami. Tsunami are long and high waves, which rise under sea due to earthquakes. It is usually a high speed wave, which rise in sea. It is also known as harbour wave.

Examples.

In 1819 on Hawain islands.
In 2004.

Effects of Tsunami.

Loss of Lives.
Loss of Aquatic life.
Physical damage of human life and property.
Uprooting of plants on the banks of sea or in coastal regions.

Question 7.
Write down the uses of electroscope.
Answer:
Uses of electroscope:

Electroscope is used to detect the presence of charge.
It is used to find the type of charge.
It is used to compare the charges.

Question 8.
What is electric discharging (lightning) ?
Answer:
Electric discharging (Lighting).
The phenomenon of lightning is caused due to discharge through air. It occurs when the charge accumulated in the clouds exceeds a certain limit. When unlike charged clouds come closer to each other, the charges in air between them move with a great velocity. Due to this, an intense spark of lightning is seen moving in the air. This is known as electric discharging or lightning.

Question 9.
Write two examples of electric discharge which are used to ignite the fuel.
Answer:
Examples of Electric discharges:

By sparkplug in scooter and car.
By electric gas lighter used to ignite the gas stove in kitchens.

Question 10.
What are natural phenomena ?
Answer:
Natural Phenomena.
The phenomena which occur suddenly in nature are called natural phenomena. They cause severe damage to life and property to related areas and environment is also affected with human life.
Examples : Earthquake, landslides, food, drought, cyclones, eruption of volcanoes, tsunami, etc.

Question 11.
What are cyclones ? Write effects and reasons caused by it.
Answer:
Cyclone.
Cyclone is a terrible storm which has a speed more than 119 km per hour.

Reasons.
When sea water evaporates in summer season, it rises up and condenses to form cloud. To get the space of upward moving air, air rushes speedily under it. There forms a cyclic motion nearby a centre or due to difference in temperature and pressure present above the hot sea water, cyclones are produced.

Effects.
Cyclones affect crops, health, ships, etc. Landslides and foods cause severe damage to mankind.

Long Answer Type Questions

Question 1.
Give an experiment to show that when two bodies are rubbed together, they get oppositely charged.
Answer:
PSEB 8th Class Science Solutions Chapter 15 Some Natural Phenomena 2
Experiment.
Take a plastic scale. Wrap flannel at its one end. Rub this side with another plastic scale. Bring these two scales separately near bits of tissue paper. We observe that both scales show attraction toward the bits of tissue paper. This proves that both the scales get charged on rubbing.

Now suspend one scale from a stand and bring the other close to it. They get attracted. It shows that they have opposite charges. It is because opposite charges attract each other. Thus, we may conclude that when two bodies are rubbed together, they get oppositely charged.

Question 2.
What is lightning ?
Answer:
Lightning.
The phenomenon of lightning is caused due to electric discharge through air. It occurs when the charge accumulated in the clouds exceeds a certain limit. In these conditions, the small region of positive charges in the lower part induces a negative charge on the ground below it. The large force of attraction between the opposite charges becomes sufficient to break down the insulation of air.

Once this happens, the entire positive charge in the lower parts of the clouds passes to the earth through a narrow gap in the air. The huge negative charge gets accumulated in the lower parts of the cloud then passes through this conducting path in a very short time. The air in this narrow gap gets heated by the electrical energy to such a high temperature that it appears as a flash of light, which we see as lightning.

Question 3.
What safety measures should we take to prevent damage caused by lightning ?
Answer:
Precautions to be taken to provide protection against lightning.
The following precautions should be taken to protect ourselves against lightning:

We should not stand under trees, when lightning occurs and even during rain, when there are chances of lightning to strike.
We should put up lightning conductor on our buildings to protect our lives and property from damage.
We should switch off TV sets during lightning for TV antennas are more prone to lightning strikes.

Question 4.
Discuss the construction and working of a lightning conductor.
Answer:
PSEB 8th Class Science Solutions Chapter 15 Some Natural Phenomena 3
Lightning Conductor.
It is a pointed long metal rod fixed along side of a building. The lower end of this rod is hurried deep under the earth.

Working of a Lightning Conductor.
A lightning conductor protects the building from the destructive effect of the lightning in two ways:
1. During a thunderstorm, a charged cloud passes above the point of the lightning conductor.
If’the cloud is positively charged, it induces a negative charge on its upper end.

This end being pointed cannot retain this charge and sends into the atmosphere a wind on negatively charged particles which cancel some of the positive charge on the clouds. This reduces the potential of the cloud below the spark potential and as such no lightning discharge takes place between the building and the cloud.

2. If a discharge actually takes place, the lightning conductor provides an easy passage to the charge from the cloud to the earth. The building is thus, saved from the destructive effects of the lightning.

Question 5.
What are causes and impacts of earthquake ? Write precautions against earthquake.
Answer:
Earthquake.
Quakes are vibrations created in the earth’s crust. These may arise suddenly.

Reason of earthquake.
Geographically our earth is made up of seven long tectonic plates. These plates move very slowly. But whenever these plates acquire high speeds, there is a disturbance on the earth’s surface. These movements of the earth’s surface cause buildings to fall, bridges, roads, etc. get broken.

Impacts of the earthquake.
Tsunami.

It is caused by Tsunami (a seismic sea wave)
Many buildings fall down.
The supply of basic amenities is disturbed.
It causes a health hazards.

Precautions against earthquakes:

In highly seismic areas timber must be used in constructions of buildings instead of heavy materials like mud, stone, brick, etc.
It is better if the cupboards and shelves are fixed to the walls so that they do not fall easily.
Be careful where you hang wall clocks, photo-frames, water heaters, etc. so that they do not fall in the event of an earthquake.
Since some buildings may catch fire due to an earthquake, hence fire fighting equipment should be installed in these buildings.

PSEB 8th Class Agriculture Solutions Chapter 7 Crop Diversification

October 15, 2024October 14, 2024 by Prasanna

Punjab State Board PSEB 8th Class Agriculture Book Solutions Chapter 7 Crop Diversification Textbook Exercise Questions and Answers.

PSEB Solutions for Class 8 Agriculture Chapter 7 Crop Diversification

Agriculture Guide for Class 8 PSEB Crop Diversification Textbook Questions and Answers

(A) Answer in one to two words:

Question 1.
Which cropping system is adopted in the sub-mountainous regions?
Answer:
Rice-Wheat.

Question 2.
Which is the main cropping system in southwestern region?
Answer:
Cotton-Wheat.

Question 3.
Give examples of multiple cropping systems.
Answer:
Maize-potato-moong, groundnut-potato-bajra.

Question 4.
How much water table is depleting every year in central Punjab due to cultivation of rice crop?
Answer:
Approximately 74 cm per year.

Question 5.
Which bacterium helps in nitrogen fixation?
Answer:
Rhizobium.

Question 6.
Which fertilizer can be saved in Dhaincha-Basmati-wheat cropping system?
Answer:
Nitrogen fertilizer.

Question 7.
Which crops are imported by India from foreign countries?
Answer:
Pulses, oil seed crops.

Question 8.
How many days before basmati transplanting, green manure should be incorporated in the field?
Answer:
Just before a day.

Question 9.
What percentage of area is under irrigation in Punjab state?
Answer:
98%.

Question 10.
How many tubewells (no.) are there in Punjab?
Answer:
Approximately 14 lakhs.

(B) Answer in one to two sentences:

Question 1.
What do you mean by crop diversification?
Answer:
Crop diversification refers to cultivation of alternate crops by reducing area under conventional crops like wheat and rice and by increasing area under the crops like-maize, pulses, basmati, sugarcane, potato, oilseed crops, etc.

Question 2.
Which crops can be grown in dry land areas?
Answer:
Oil seed crops can be grown in such land areas.

Question 3.
Enlist maize based cropping systems.
Answer:
Maize-potato-summer moong or sunflower, maize-potato or toria- sunflower, maize-potato-onion or mentha and maize-gobhi sarson moong.

Question 4.
Enlist fodder based cropping systems.
Answer:
Maize-Berseem-Bajra, Maize-Berseem-Maize or Cowpea.

Question 5.
Write significance of intensive cropping system.
Answer:

High yield can be taken from small land holding.
Climate changes can be tackled.
Use of chemical fertilizers is reduced.
Balanced nutrition in maintained and employment opportunities are increased.
Agro-ecosystem is maintained and it helps in conserving natural resources.

Question 6.
Which enterprises can be adopted in integrated farming system?
Answer:
Following enterprises can be adoped in integrated farming system-

Fish farming
Cultivation of fruits
Cultivation of vegetable
Dairy farming
Rabbit farming
Pig farming
Goat farming
Bee keeping
Poultry farming
Agroforestry like poplar.

Question 7.
Write about source of irrigation in Punjab.
Answer:
Approximately 98% of area in Punjab is under irrigation. There are nearly 14 lakhs tubewells in Punjab. Canal irrigation is also adopted.

Question 8.
Name the alternate crops which can be cultivated in central Punjab over rice-wheat
Answer:
Maize, Potato, Pea, Sugarcane, Basmati, Sunflower, Muskmelon, Chilli and other vegetables.

Question 9.
Write the names of main crops cultivated in sub-mountainous region.
Answer:
Main crops cultivated in sub-mountainous region are-wheat, maize, paddy, basmati, potato, oil seed crops and peas.

Question 10.
Which cropping systems should be adopted in areas having light soils?
Answer:
Groundnut based cropping system can be adoped in light soils, e.g. gsoundnut-potato or toria or wheat, groundnut- potato-bajra (fodder), groundnut- toria or gobhi sarson.

Question 1.
What do you mean by crop diversification? Write about its aim and significance?
Answer:
Crop diversification:
Crop diversification refers to cultivation of alternate crops by reducing area under conventional crops; like, wheat and rice and by increasing area under the crops like-maize, pulses, basmati, sugarcane, potato, oilseed crops etc.

Aim: Aims of crop diversification are:

Judicious use of natural resources and conserving them for future and for long time.
To get more income by investing less on growing crops.
To get out of the same crop rotation cycle so that soil and water remain conserved.

Significance:
Rice-wheat cropping cycle requires 215 cm water in a year and out of this water 80% is consumed by rice crop. Cultivation of rice is damaging the physical and chemical properties of the soil. For the last 50 years area under cultivation of rice has increased at the cost of area under groundnut, oil seed crops, cotton, pulses etc. Crop diversification is the reverse of this process and lot of water is saved and soil health is also improved.

Question 2.
Why there is need for crop intensification? Describe in detail with examples?
Answer:
Intensive cropping system means sowing more than two crops in a year. Crops are sown in the time between the harvesting of first crop and sowing of next crop.
Need for crop intensification:

High yield can be taken from small land holding.
Climate changes can be tackled.
Use of chemical fertilizers is reduced.
Balanced nutrition is maintained and employment opportunities are increased.
Agro-ecosystem is maintained and it helps in conserving natural resources.

Cultivation of leguminous crops help in increasing the soil fertility by fixation of nitrogen with rhizobium. This saves nitrogen fertilizers. Important multiple cropping patterns are –

Green manuring based; e.g. Jantar-Maize etc.
Maize based; e.g. maize-potato-moong or sunflower.
Soyabean based ; e.g. soyabean-wheat-cowpea
Groundnut based; e.g. – Groundnut – potato-toriya,.
Green fodder based; e.g. – Maize – berseem- bajra.

Question 3.
Write about the problems related to agriculture in Punjab.
Answer:
Problems related to agriculture in Punjab are as follows:

After green revolution Punjab remained stuck in the crop cycle of paddy and wheat. Due to cultivation of these two crops water table is going down and excess use of chemicals like weedicides, pesticides and fertilizers etc. has damaged the health of the soil and also badly affected the chemical and physical properties of the soil.
Area under oil seed crops and pulses is reducing.
Due to heavy rainfall in south-western zone there exists problem of soil erosion.
Water level is going down by 74 cm every year and farmers have to use submersible motor for lifting water,
which adds to the cost of cultivation.
New species of insectes and weeds are being generated.
Biodiversity is decreasing.
Climate changes are taking place.

Question 4.
What is integrated farming system? Describe in detail with examples.
Answer:
In Integrated farming system a farmer can adopt one or two additional enterprises other than agriculture. This way farmer can increase his income and his family members can also help in the “’enterprise. (Integrated forming system IFS) helps in meeting the nutritional food requirements of the family. Some of the enterprises which a farmer can adopt from:

Fish farming.
Cultivation of fruits
Cultivation of vegetables
Dairy farming
Rabbit farming
Pig farming
Goat farming
Bee keeping
Poultry farming
Agroforestry like, poplar.

Question 5.
What do you mean by inter cropping system? Describe with examples.
Answer:
Intercropping system. Inter cropping is also called mixed cropping system. Inter cropping is done to get high yield from small land holding, get higher income and to fulfil requirements of the population.

Due to increase in factories, expansion of residential areas, land under cultivation is decreasing day by day. Therefore, it is the need of the hour to obtain maximum yield from the available land. For this inter cropping is done e.g. Maize or moong, Arhar or moong, Soyabean or moong, Maize or soyabean, Maize or maize for green fodder or groundnut, Cotton or maize etc. Due to intercropping there is no bad effect on the yield of the main crop. This system helps in maintaining the soil fertility. Problem of weeds is also reduced to large extent.

PSEB 8th Class Agriculture Guide Crop Diversification Important Questions and Answers

Very Short Answer Type Questions

Question 1.
How much land is under the cultivation of rice?
Answer:
Approximately 28.3 lakhs hectare.

Question 2.
How much land is under the cultivation of wheat?
Answer:
Approximately 35.1 lakhs hectare.

Question 3.
For the last 50 years, at the cost of which crops area under the cultivation of rice has increased?
Answer:
Groundnut, oil seed crops, sugarcane, pulses.

Question 4.
How much water is consumed by rice-wheat crop cycle in a year?
Answer:
215 cm.

Question 5.
How much water is consumed by rice crop out of total water consumed in a year by rice-wheat crop cycle?
Answer:
80%

Question 6.
How much total area in Punjab is under the cultivation of various crops?
Answer:
41.58 lakhs hectare.

Question 7.
In how many zones has Punjab been divided on agroclimatic basis?
Answer:
Three zones-sub mountainous zone, central zone, south-western zone.

Question 8.
Submountainous zone lies at foothills of which hill?
Answer:
Himalayan foothills.

Question 9.
How much area under sub-mountainous region is covered by Kandi belt?
Answer:
Approximately 9%

Question 10.
Which is the main crop cycle in Punjab?
Answer:
Wheat-rice.

Question 11.
Which crop rotation cycle is adopted in South-Western Zone?
Answer:
Cotton-Wheat.

Question 12.
What is the quality of ground water in south-western zone?
Answer:
Its is saline or saline sodic.

Question 13.
Name the crops used as green manure.
Answer:
Jantar, Rawanh (Cowpea).

Question 14.
If maize is to be sown then for how many days before green manure should be ploughed in the fields?
Answer:
8-10 days before sowing maize.

Question 15.
Dried bits of which crop can be used as green manure?
Answer:
Summer moong.

Question 16.
How much protein content is contained in soyabean?
Answer:
35-40%.

Question 17.
Which crop contributed a lot in bringing white revolution?
Answer:
Fodder crops.

Question 18.
How much fodder is given to cows and buffaloes on daily basis for higher milk yield?
Answer:
40 kg green fodder.

Question 19.
Write vegetable based crop system for villages which are near to city.
Answer:
Cauliflower-tomato-ladyfinger.

Question 20.
Write vegetable based crop system for villages which are far away from city.
Answer:
Potato-ladyfinger-early sown cauliflower.

Short Answer Type Questions

Question 1.
What do you know about Kandi area?
Answer:
It is the nearly 9% area under the sub-mountainous zone.

Question 2.
What is the problem found in central zone of Punjab?
Answer:
The cropping cycle adoped in this zone is of wheat-rice and due to this cycle underground water is going down at the rate of 74 cm per year.

Question 3.
Why is soyabean best alternate for rice crop?
Answer:
Rice yield is decreased due to attack of insects and pests and diseases. Therefore, soyabean is best alternate for rice crop.

Question 4.
What is the advantage of inter cropping system?
Answer:
Inter cropping system is helpful in maintaining the fertility of the soil. Problem of weeds is also decreased to large extent.

Question 5.
Suggest vegetable cropping system for farms which are nearby city.
Answer:

Brinjal (long)- late cauliflower-bottle gourd
Potato – muskmelon
Spinach-knol khol- onion or green chilli or radish.
Cauliflower – tomato-ladyfinger.

Long Answer Type Question

Question 1.
Suggest maize based and soyabean based cropping systems.
Answer:
1. Maize based cropping system-
Some of the maize based cropping systems are:

Maize – Potato – Moong or sunflower.
Maize – Potato or toria – sunflower
Maize-potato – onion or mentha etc.

These cropping systems help in conserving the natural sources.

2. Soyabean based cropping system-
Soyabean based cropping system is-Soyabean – wheat- rawanh (Cowpea) (fodder)
Rice yield is decreased due to attack of insects and p@6ts and diseases. Therefore soyabean is best alternate for rice crop. Soyabean is a leguminous crop. It helps in fixing nitrogen in the soil and thus helps in maintaining the fertility of the soil. Soyabean is a good source of protein. It contains nearly 35-40% protein content. It is used to prepare soya milk, soya cheese, soyanutri etc.

PSEB 8th Class Physical Education Solutions Chapter 6 Sports and Discipline

October 14, 2024October 13, 2024 by Prasanna

Punjab State Board PSEB 8th Class Physical Education Book Solutions Chapter 6 Sports and Discipline Textbook Exercise Questions and Answers.

PSEB Solutions for Class 8 Physical Education Chapter 6 Sports and Discipline

Physical Education Guide for Class 8 PSEB Sports and Discipline Textbook Questions and Answers

Question 1.
What is the relation between Sports and Discipline?
Answer:
Sports have a very deep relation with discipline because one cannot achieve victory without discipline in sports. Sports causes development in the behaviour of player/sportsperson. Discipline plays an important role in building up the character of a player and without discipline, a good character cannot be developed. Lack of discipline causes several problems in the life of a player which further gets tough for the player to overcome.

No example can be better than that of the ‘Nature’, everything is disciplined as far as the functioning of Nature is concerned. For example; the sunrise and sunset always occur timely and with strict discipline; earth revolves around the sun with a fixed speed and time, likewise, there must be a proper and strict discipline in the life of an individual as well.

If an individual wants to become a successful player, he/she should practice discipline right from childhood because discipline can be developed aptly in one’s childhood. Sports teach discipline to the player in a way because sports demand obedience, co-operation, honesty, peace of mind and responsibility, which in turn brings discipline in the life of a player. It can be concluded that discipline is the key to success, and discipline can be easily achieved through sports.

Question 2.
What is the meaning of Discipline?
Answer:
Meaning of Discipline. Discipline means to follow the rules strictly or everybody should perform all his duties. Every citizen should remain in discipline. “Discipline makes a nation great” is a well-known saying. If every citizen is disciplined, the nation can make rapid progress. By abiding all rules and regulations, a citizen can make his contribution to his society or country.

Question 3.
What are the types of discipline?
Answer:
Types of Discipline.
Discipline is of two types:

1. Self Discipline
2. Forced Discipline or Commanded Discipline.

1. Self Discipline:
The feeling of abiding by the rules comes from his own and perform his duties without any external command. This is permanent discipline.

2. Forced Discipline.
In forced discipline the rules and regulations are followed by command or the directions of someone. This type of discipline is temporary. Forced discipline will remain only upto that time when you have a fear of someone or a person who commands on your head. Out of these, self discipline is better. Children must have the feeling to be self-disciplined, so that they may become good students or good citizens.

Question 4.
What is the need and importance of discipline?
Answer:
Importance of Discipline in our life. Discipline is a milestone of our society. Without discipline man can’t move in society. If every citizen is disciplined the nation can make rapid progress. By abiding the rules, a good citizen can make his contribution to his society or country. Discipline is the base of every caste, creed, society and country. In every sphere of life, Discipline is needed. Importance of Discipline is known by the following facts:

Discipline makes a good student an ideal citizen.
Disciplined boys learn to respect their teachers, parents and elders.
Through Discipline children become obedient.
Disciplined children behave nicely with others.
Disciplined boys become punctual.
Discipline develops the personality of a person.
Discipline develops good habits and good qualities in a person.
Discipline helps to reform social life.
Discipline makes the society and the nation more strong.
Discipline makes a nation strong and keeps it strong.
Discipline helps the society and country for its progress and happy life of their citizens.
Discipline helps a person to lead a successful and happy life.
Discipline also protects the country from foreign invaders.
Discipline helps to run school, house and other organisations smoothly.
Discipline helps a person for his harmonious development of his personality.
Disciplined labour can increase the production of their factory.
Discipline assists a person for his mental development because a person performs his duties after proper thinking and according to rules.

One should remain in discipline to lead a successful life. Home, School, Play fields are such places where a person gets an opportunity to remain in discipline.

Question 5.
How do the sports create discipline in Hie life of the students?
Answer:
Sport and discipline are integral part of each other. Victory can not be achieved without discipline. Sports build the character of the players. Discipline plays an important role in character. building. Character building is impossible without discipline because indiscipline creates many problems in the life of a player. It becomes difficult for a player to overcome these problems. The nature works in discipline. The sun rises in the east in the morning and sets in the west in the evening.

The earth moves in an order. Similary discipline is very important in the life of a human being. We can teach discipline in better way to the children. Sports create discipline in the innocent mind of the children. Sports teaches them to be disciplined because sports teaches punctuality, coordination, leadership, honesty, and sense of responsibility to fulfil their duties. Discipline is the key to success because it creates opportunity to succeed.

PSEB 8th Class Physical Education Guide Sports and Discipline Important Questions and Answers

Multiple Choice Questions

Question 1.
Types of discipline :
(A) Two
(B) Three
(C) Four
(D) Five.
Answers:
(A) Two

Question 2.
Importance of discipline:
(A) Children become obedience.
(B) Disciplined boys behave good with others.
(C) Discipline causes to do the work on time.
(D) Above all.
Answers:
(D) Above all.

Question 3.
Sports and discipline are related:
(A) There is discipline in sports.
(B) Discipline develops character in sports man.
(C) Without discipline character cannot be developed.
(D) Above all.
Answers:
(D) Above all.

Question 4.
These qualities belongs to:
(A) Punctuality
(B) Obedience
(C) Tolerance
(D) All above in discipline.
Answers:
(D) All above in discipline.

Question 5.
Why indiscipline is harmful for the country?
(A) Country cannot remain happy.
(B) Country cannot progress.
(C) Country will depend on other countries.
(D) All Above.
Answers:
(D) All Above.

Very Short Answer Type Questions

Question 1.
What do you mean by obeying the rules or remain in control?
Answer:
Discipline.

Question 2.
On which thing the ancient institution used to stress mostly?
Answer:
To be disciplined.

Question 3.
How students behave these days in their institutions?
Answer:
Indiscipline.

Question 4.
How is the nation built and how it remains stable?
Answer:
Through discipline.

Question 5.
What type of education discipline provides to the children?
Answer:
Obedience.

Question 6.
Discipline develops the personality. How?
Answer:
Mental development.

Question 7.
How the quality of discipline is improved?
Answer:
Games and sports.

Question 8.
Whose important place is there to instil discipline in students.
Answer:
The important place to instil discipline in student is teacher.

Short Answer Type Questions

Question 1.
Children learn discipline at Home. How?
Answer:
Home is the first school of Discipline for children. Parents, grandmother, grandfather; uncle and aunty, brothers and sisters live together in a house. The elder person in family leads it in all activities. All other follow him according to the sweet will of his elders. Everyone love each others and respect to the elders. Everybody share their happy and sorrows. They had very congenial and wholesome atmosphere of his family. All the members of the family perform their duties. In such congenial atmosphere children remain in discipline. They start to be in discipline from his house in their childhood, small children respect elders and follow them.

Question 2.
How sports developed discipline in students.
Answer:
School and discipline. Atmosphere of the school provides training to the students for discipline. In school, students respect their teachers and obey them. They live together with their friends and co-students. Playing, and sitting together become their habits. They attend their school in time and do their home work regularly. They are afraid of theft and telling lie and help each other. These qualities become part and parcel of their character.

All the teacher obey the order of the headmaster and other workers follow him in carrying the order of the teacher, everything is performed in a disciplined way in the school. The students start learning discipline in such type of atmosphere of the school. In this way, environment of school is helpful in teaching their students about discipline.

Question 3.
Do our society and our country need discipline? Write your ideas.
Answer:
Man is a social animal. He has to depend upon others for the satisfaction of many of his needs. He cannot live alone. He cannot fulfil all his desires all alone. We have to take help from one another in some work. We can not disobey the rules of our society. To imbide the rules of our society we have to remain in discipline people can get benefits by obeying Laws in other fields of life. The society will be stable if we remain in discipline. Indiscipline is harmful for the society.

Law treats all men as equal. Therefore, it is the duty of every person to obey Law. Law are made for the welfare of the people . Our society and country are facing so many troubles from outside and within the country to safe the country from foreign invasion. Everyone should obey rules and laws in life and lead an organised and disciplined life. A country can progress only if has inhabitants leads disciplined life. For the progress of the country the whole society must be disciplined. Indiscipline is not in favour of the country. We should not go against the country. So we can say that our society and country needs Discipline.

Question 4.
Why indiscipline is harmful for the country?
Answer:
It is the duty of every citizen to obey laws and to be disciplined.

Indiscipline is harmful to our society.
For the development and progress of the country discipline is the need of the hour. Discipline has great importance for the citizen of the country to develop and for stability.
Indiscipline is very very harmful to the nation.
Students, labourers, and so many others employees, of Govt, and private institutions go on strike and destroy the national property. Such type of indiscipline is not in favour of the welfare of our country.

Everybody is aware that he can play an important role to form government because government is for the people, by the people and of the people. Laws are made by the government and the people has to obey these Laws. If the countrymen are indisciplined it causes internal disturbance, thereby causing foreign forces to attack. So a country cannot progress due to indiscipline.

PSEB 8th Class Science Solutions Chapter 14 Chemical Effects of Electric Current

October 14, 2024October 13, 2024 by Prasanna

Punjab State Board PSEB 8th Class Science Book Solutions Chapter 14 Chemical Effects of Electric Current Textbook Exercise Questions and Answers.

PSEB Solutions for Class 8 Science Chapter 14 Chemical Effects of Electric Current

PSEB 8th Class Science Guide Chemical Effects of Electric Current Textbook Questions and Answers

Exercises

Question 1.
Fill in the blanks.
(a) Most liquids that conduct electricity are solutions of ……………….. , ………………. and ………………. .
(b) The passage of an electric current through a solution causes ……………….. effects.
(c) If you pass current through copper sulphate solution copper gets deposited on the plate connected to the ………………… terminal of the battery.
(d) The process of depositing a layer of any desired metal on another material, by means of electricity is called ……………………… .
Answer:
(a) acid, bases, salts.
(b) chemical
(c) negative (- ve)
(d) electroplating.

Question 2.
When the free ends of a tester are dipped in a solution, the magnetic compass needle shows deflection. Can you explain the reason ?
Answer:
Deflection of compass needle is due to conduction of electricity through the solution because the solution is good conductor.

Question 3.
Name three liquids, which when tested in a manner shown in fig. may causes the magnetic needle to deflect.
PSEB 8th Class Science Solutions Chapter 14 Chemical Effects of Electric Current 1
Answer:

Acid
Base
Acidulated water.

Question 4.
The bulb does not glow in the setup shown in fig. List the possible reasons. Explain you answer.
PSEB 8th Class Science Solutions Chapter 14 Chemical Effects of Electric Current 2
Answer:
The set up shows no glowing of the bulb but it does not mean that liquid is not conducting electricity. Liquid may be so weak electrolyte that it can not make the bulb glow. So, to test it for surity, LED can be used, which glows for very minute currents.

Question 5.
A tester is used to check the conduction of electricity through two liquids labelled A and B. It is found that the bulb of the tester glows very brightly for liquid A while it glows dimly for liquid B. You would conclude that.
(i) liquid A is better conductor than liquid B.
(ii) liquid B is better conductor than liquid A.
(iii) both liquids are equally conducting.
(iv) conducting properties of liquids cannot be compared in this manner.
Answer:
(i) Liquid A is better conductor than liquid B.

Question 6.
Does pure water conduct electricity ? If not, what can we do to make it conducting ?
Answer:
Pure water does not conduct electricity but it can be made good conductor by adding few drops of dil. sulphuric acid. The water so obtained is called acidulated water.

Question 7.
In case of a fire, before the firemen use the water hoses, they shut off the main electrical supply for the area. Explain why they do this.
Answer:
Pure water is an insulator but tap water is a good conductor of electricity. To avoid electrocuting, firemen manually shut off the supply before using water hoses.

Question 8.
A child staying in the coastal regions tests the drinking water and also the sea water with his tester. He finds that the compass needle deflects more in case of sea water. Can you explain the reason ?
Answer:
Since sea water is rich in salt concentration. So, compass needle is more deflected in sea water as compared to the drinking water available in coastal areas.

Question 9.
Is it safe for electrician to carry out electrical repairs outdoor during heavy downpour ? Explain.
Answer:
No, it is not safe for a wireman to carry out electrical repairs during heavy down pour because water (Impure) is a conductor of electricity. So, wireman can get electric shock.

Question 10.
Paheli had heard that rain water is as good as distilled water. So she collected some rainwater in a clean glass tumbler and tested it using a tester. To her surprise she found that compass needle showed deflection. What could be the reasons ?
Answer:
No doubt, rain water is pure like distilled water. But then environment is contaminated with many impurities. These impurities get dissolved in rain water, making it a conductor of electric current.

Question 11.
Prepare a list of objects around you that are electroplated.
Answer:
Electroplated objects.

Handle bar of cycle.
Wheel rims.
Artificial ornaments.
Bath taps.
Kitchen gas burners.

Question 12.
The process that you saw in Activity 14.7 is used for purification of copper. A thin plate of pure copper and a thick rod of impure copper are used as electrodes. Copper from impure rod is sought to be transferred to the thin copper plate. Which electrode should be attached to positive terminal of the battery and why ?
Answer:
Thick rod of impure copper is to be attached to positive terminal of battery as pure copper moves to electrode connected to negative terminal of the battery.

PSEB Solutions for Class 8 Science Chemical Effects of Electric Current Important Questions and Answers

Multiple Choice Questions

Question 1.
In order to keep the flow of electricity continue in circuit, which of the following items should be used in place of iron nail in the given circuit.
PSEB 8th Class Science Solutions Chapter 14 Chemical Effects of Electric Current 3
(a) Graphite
(b) Plastic
(c) Wood
(d) Rubber.
Answer:
(a) Graphite.

Question 2.
Pankaj knows that pure water is bad conductor of electricity. If you dissolve salt in water then what will happen ?
(а) Water will become good conductor of electricity.
(b) Water will remain bad conductor of electricity.
(c) Water will neither be a good conductor nor a bad conductor of electricity.
(d) None of the above.
Answer:
(a) Water will become good conductor of electricity.

Question 3.
Which out of the following is insulator of electricity ?
(a) Acid
(b) Bases
(c) Pure water
(d) Solutions of salt
Answer:
(c) Pure water

Question 4.
Which out of the following is not an insulator ?
(a) Rubber
(b) Plastic
(c) Wood
(d) Copper
Answer:
(d) Copper

Question 5.
What is the effect of passing electric current through the solution of electrolytes ?
(a) Magnetic effect
(b) Heat effect
(c) Chemical effect
(d) None of these.
Answer:
(c) Chemical effect.

Question 6.
Which effect of electric current is used in electroplating ?
(a) Magnetic effect
(b) Chemical effect
(c) Heat effect
(d) None of these.
Answer:
(b) Chemical effect

Question 7.
The availability of some amount of impurities make water:
(a) conductor
(b) insulator
(c) pure
(d) none of these.
Answer:
(a) conductor.

Question 8.
A tester is used to check the conduction of electricity through two liquids labelled A and B. It is found that the bulb of the tester glows very brightly for liquid A while it glows dimly for liquid B, you would conclude that:
(а) Liquid A is better conductor than liquid B
(b) Liquid B is better conductor than liquid A
(c) Both liquids are equally conducting
(d) Conducting properties of liquids cannot be compared in this manner.
Answer:
(a) liquid A is better conductor-than liquid B.

Very Short Answer Type Questions

Question 1.
Is human body a conductor or an insulator ?
Answer:
Conductor.

Question 2.
What are conductors ?
Answer:
Conductors.
Materials like silver, copper, aluminium, iron and human body etc. which allow electric current to pass through them, are called conductors.

Question 3.
What are insulators ? Give two examples.
Answer:
Insulators.
Materials like wood, rubber, silk, plastic etc. which do not allow electric current to pass through them, are called insulators.

Question 4.
Do all liquids allow electric current to pass through them ?
Answer:
No.

Question 5.
What is LED ? ,
Answer:
LED-Light Emitting Diode.

Question 6.
Name the phenomenon of breaking up of a chemical compound under the action of electric current.
Answer:
Electrolysis.

Question 7.
What do we get on electrolysis of acidulated water ?
Answer:
Hydrogen gas and Oxygen gas.

Question 8.
Which effect of current is used in electroplating ?
Answer:
Chemical effect.

Question 9.
Which effect of current makes a bulb glow ?
Answer:
Heating effect.

Question 10.
How can small current be tested ?
Answer:
By using LEDs.

Question 11.
Name different effects of electric current.
Answer:

Heating effect,
lighting effect,
chemical effect and
magnetic effect.

Question 12.
Is air an insulator ?
Answer:
Yes.

Question 13.
Name few liquids which can conduct electricity.
Answer:
Lime water, lemon juice, vinegar, tap water.

Question 14.
Can conductors be classified as insulators or vice versa under special conditions ?
Answer:
Yes.

Question 15.
Which commonly used liquids can conduct electricity ?
Answer:
Solution of acids, bases and salts.

Question 16.
What are electrodes ?
Answer:
Electrodes.
Metallic rods or plates immersed in electrolytes to make contact with battery, are called electrodes.

Question 17.
By which phenomenon cheap articles are coated with gold or expensive metals ?
Answer:
Electroplating.

Question 18.
Is electroplating useful process ?
Answer:
Yes.

Short Answer Type Questions

Question 1.
Air is a bad conductor of electricity. Show with an experiment.
Answer:
Air-a bad conductor of electricity.
Take a battery bulb and connect it to a cell and a switch. When the switch is fixed with a safety pin then the current flows and bulb glows, but when safety pin is removed then there is only air between the gap of switch and current does not flow. It shows that air is bad conductor of electricity.

Question 2.
What is electrolysis ?
Answer:
Electrolysis.
Breaking up of chemical compounds under the action of electric current, is called electrolysis. When we pass electric current through water (acidulated), it breaks up into its constituents : hydrogen and oxygen. Hydrogen is liberated at the cathode whereas oxygen is liberated at the anode.

Question 3.
What is electroplating ?
Answer:
Electroplating.
Process of electrolysis is used to deposit thin layers of valuable metals (like zinc, silver or gold) on cheaper metals by the passage of electricity through electrolyte to save them from rusting whereas to give them a decorative look. This process is called electroplating.

Question 4.
Give a brief account of LED.
Answer:
PSEB 8th Class Science Solutions Chapter 14 Chemical Effects of Electric Current 4
LED.
It is light emitting diode. It glows even when the current is .very small. It consists a bulb with two legs called leads. One leg is longer and other leg is shorter.
Longer leg is attached to +ve terminal of battery and shorter leg is attached to -ve terminal.

Long Answer Type Questions

Question 1.
Is water a good conductor ? What happens when common salt is added to water ?
Answer:
PSEB 8th Class Science Solutions Chapter 14 Chemical Effects of Electric Current 5
Pure or distilled water is an insulator.
Experiment.
Dip two carbon rods in distilled water and connect it to a bulb, 6 V battery and a key. The bulb will not light up showing that distilled water is a bad conductor of electricity.

Now replace distilled water by water mixed with common salt. The bulb will at once light up, when key is introduced. This shows that distilled water is perfectly insulator, impure water specially one containing common salt is highly conducting.

Question 2.
What is electroplating ? Give its uses.
Answer:
PSEB 8th Class Science Solutions Chapter 14 Chemical Effects of Electric Current 6
Electroplating.
It is the process by which a costlier metal is deposited on base or cheap metal by passing current through its salt solution. When an electric current is passed through an electrolyte (the compound) breaks up into its constituent ions.

Positive ions are attracted towards cathode (negative electrode) and negative ions are attracted towards anode (positive electrode). This process of electrolysis is used in plating materials with a thin coat of metals is called electroplating.

Uses of Electroplating:

Iron is electroplated with nickel or chromium to prevent it from rusting.
Artificial jewellery, made from cheap metals is electroplated with expensive metals like gold and silver to give it an attractive look.
Handle bars of cycle, wheel rims, car parts etc. are coated with chromium to give a shiny look.
Tin cans are made by electroplating a layer of tin on the iron.

Question 3.
How can a spoon be copper plated ?
Answer:
PSEB 8th Class Science Solutions Chapter 14 Chemical Effects of Electric Current 7
Experiment.
Take a spoon that is to be electroplated with copper. Take a copper plate and make it anode by connecting it to the positive terminal of the battery. The spoon is connected to the negative terminal of the battery. A rheostat (Variable resistance); key and ammeter are also connected in series as shown. CuSO4 solution is put in a glass vessel. A rheostat is adjusted till a proper current flows through electrolyte [For best electroplating 1A of current should be passed for every 100 cm2 of the surface to be electroplated say if the area of a spoon on both sides is 60 cm2, a current of 0.6 A should be passed.] Pass the current for 5-10 minutes, till a layer of shinning copper is seen deposited on a spoon.

PSEB 8th Class Science Solutions Chapter 17 Stars and the Solar System

October 14, 2024October 13, 2024 by Prasanna

Punjab State Board PSEB 8th Class Science Book Solutions Chapter 17 Stars and the Solar System Textbook Exercise Questions and Answers.

PSEB Solutions for Class 8 Science Chapter 17 Stars and the Solar System

PSEB 8th Class Science Guide Stars and the Solar System Textbook Questions and Answers

Exercises

Question 1.
Which of the following is NOT a member of the solar system?
[a] An asteroid
[b] A satellite
[c] A constellation
[d] A comet
Answer:
[d] A comet.

Question 2.
Which of the following is NOT planet of the sun?
[а] Sirius
[b] Mercury
[c] Saturn
[d] Earth
Answer:
[a] Sirius.

Question 3.
Phases of the moon occur because
(a) we can see only that part of the moon which reflects light towards us.
(b) our distance from the moon keeps changing.
(c) the shadow of the earth covers only a part of moon’s surface.
(d) the thickness of the moon’s atmosphere is not constant.
Answer:
(a) We can see only that part of the moon which reflects light towards us.

Question 4.
Fill in the blanks.
(а) The planet which is farthest from the sun is …………………….. .
(b) The planet which appears reddish in colour is …………………… .
(c) A group of stars that appear to form a pattern in the sky is known as a …………………….. .
(d) A celestial body that revolves around a planet is known as ………………………. .
(e) Shooting stars are actually not ………………………………….. .
(f) Asteroids are found between the orbits of ……………………. and …………………………… .
Answer:
(a) Neptune
(b) Mars
(c) Constellation
(d) Satellite
(e) Stars
(f) Mars, Jupiter.

Question 5.
Mark the following statements as true (T) or false (F) :
(a) Pole star is a member of our solar system. ()
(b) Mercury is the smallest planet of the solar system. ()
(c) Uranus is the farthest planet in the solar system. ()
(d) INSAT is an artificial satellite. ()
(e) There are nine planets in the solar system. ()
(f) Constellation Orion can be seen only with a telescope. ()
Answer:
(a) (T)
(b) (T)
(c) (F)
(d) (T)
(e) (F)
(f) (F).

Question 6.
Match items in column A with one or more items in column B
Answer:

Column A	Column B
(i) Inner planets	(a) Saturn
(ii) Outer planets	(b) Pole star
(iii) Constellation	(c) Great Bear
(iv) Satellite of the earth	(d) Moon
	(e) Earth
	(f) Orion
	(g) Mars

Answer:

Column A	Column B
(i) Inner planets	(e) Earth
	(g) Mars
(ii) Outer planets	(a) Saturn
(iii) Constellation	(c) Great Bear
	(f) Orion
(iv) Satellite of the Earth	(d) Moon

Question 7.
In which part of the sky can you find Venus if it is visible as an evening star?
Answer:
In west part of the sky.

Question 8.
Name the largest planet of the solar system.
Answer:
Jupiter.

Question 9.
What is a constellation? Name any two constellations.
Answer:
Constellations are small groups of stars appearing in the space having specific common shapes. All the stars of a group always stay together and their positions are fixed relative to each other e.g. Ursa Major.

Question 10.
Draw sketches to show the relative positions of prominent stars in
(a) Ursa Major
(b) Orion.
Answer:
PSEB 8th Class Science Solutions Chapter 17 Stars and the Solar System 1

Question 11.
Name two objects other than planets which are members of the solar system.
Answer:
Asteroids, Meteors, Natural satellite.

Question 12.
Explain how you can locate the Pole Star with the help of Ursa Major.
Answer:
PSEB 8th Class Science Solutions Chapter 17 Stars and the Solar System 2
Ursa major changes its position in the sky after every three hours, it appears to revolve around fixed star. This fixed star is pole star.

Question 13.
Do all the stars in the sky move? Explain.
Answer:
All the stars except pole stars, appear to move in the sky from east to west as the earth rotates from west to east about its axis. Pole star is situated in the direction of axis of the earth, so it appears to be stationary.

Question 14.
Why is the distance between stars expressed in light years? What do you understand by the statement that a star is eight light-years away from the earth?
Answer:
Distance between the stars is very large. It is of the order of millions or billions kilometres. So, it is not convenient to express the distance in kilometres. So another larger unit called light-year is used to express distance between the stars. It can be defined as distance travelled by light in one year.

When a star is 8 light-years from the earth it means, light with speed of 3 × 10⁸ m/sec, takes 8 years to cover that distance from earth to that star.
Now 1 light year = 9.46 × 10¹⁵ m
.’. 8 light years = 8 × 9.45 × 10¹⁵ m
= 75.6 × 10¹⁵ m
So, earth is 7.56 x 1016 m away from the given star.

Question 15.
The radius of Jupiter is 11 times the radius of the Earth. Calculate the ratio of the volumes of Jupiter and the Earth. How many Earths can Jupiter accommodate?
Answer:
Let R be radius of the Earth.
then volume of the Earth = \(\frac{4}{3} \pi \mathrm{R}^{3}\)
and volume of Jupiter = \(\frac{4}{3} \pi \mathrm{R}^{\prime 3}\)
= \(\frac{4}{3} \times \pi(11 \mathrm{R})^{3}\) [as R’= 11R]
Now Ratio = \(\frac{\text { Volume of the Earth }}{\text { Volume of the Jupiter }}=\frac{\frac{4}{3} \pi \mathrm{R}^{3}}{\frac{4}{3} \pi(11 \mathrm{R})^{3}}=\frac{1}{1331}\)
or 1:1331

Question 16.
Bojo made the following sketch of the solar system. Is the sketch correct ?.’If not, correct it.
PSEB 8th Class Science Solutions Chapter 17 Stars and the Solar System 3
Answer:

PSEB Solutions for Class 8 Science Stars and the Solar System Important Questions and Answers

Multiple Choice Questions

Question 1.
Parvinder saw a constellation in the sky in a clear dark night. Name this constellation.
PSEB 8th Class Science Solutions Chapter 17 Stars and the Solar System 5
(a) Saptarishi
(b) Orion
(c) Cassiopia
(d) None of the above.
Answer:
(a) Sapatrishi.

Question 2.
The planet which is nearest to the sun?
(a) Earth
(b) Mercury
(c) Saturn
(d) Venus
Answer:
(b) Mercury.

Question 3.
Which planet is called red planet?
(a) Mars
(b) Mercury
(c) Venus
(d) Jupiter
Answer:
(a) Mars

Question 4.
Which is the brightest planet at night?
(a) Mercury
(b) Earth
(c) Venus
(d) Mars
Answer:
(c) Venus.

Question 5.
The planet which is farthest from the Sun is :
(a) Neptune
(b) Jupiter
(c) Mercury
(d) Earth
Answer:
(a) Neptune.

Question 6.
Name the first Indian Artificial satellite.
(a) INSAT
(b) IRS
(c) Arya Bhatta
(d) Kalpana-I
Answer:
(c) Arya Bhatta.

Question 7.
Name the planet of the solar system where life exists.
(a) Mercury
(b) Earth
(c) Mars
(d) Saturn
Answer:
(b) Earth.

Question 8.
Which of the following is not the member of solar system?
(a) An asteroid
(b) A satellite
(c) A constellation
(d) A comet
Answer:
(c) A constellation.

Question 9.
Which of the following is not planet of the solar system?
(a) Sirius
(b) Mercury
(c) Saturn
(d) Earth
Answer:
(a) Sirius.

Very Short Answer Type Questions

Question 1.
Name the star closest to earth other than sun.
Answer:
Alpha century.

Question 2.
How much time does light take to reach us from Alpha century.
Answer:
4.3 years.

Question 3.
Which constellation looks like a big kite with a tail?
Answer:
Ursa-major constellation.

Question 4.
Name the constellation which looks like a cluster of twinkling gems in the night sky.
Answer:
Pleides constellation.

Question 5.
Define a light year.
Answer:
Light year. It is the distance travelled by light with a speed of 3,00,000 km/ hr in one year.
1 light year = 9.46 × 10¹² km.

Question 6.
How far is the sun from the earth?
Answer:
The sun is at a distance of 1.5 × 10⁸ km from the earth.

Question 7.
Which planet is known as the red planet?
Answer:
Mars.

Question 8.
Which planet rotates on its axis from East to West?
Answer:
Uranus.

Question 9.
Which force hold the planets in their orbits around the sun?
Answer:
Gravitational force of the sun holds the planets in their orbits around the sun.

Question 10.
What are Asteroids?
Answer:
Asteroids. The small solid objects made up of rocks and minerals, which move in the gap between the orbits of the Mars and Jupiter are called Asteroids.

Question 11.
What are meteorites?
Answer:
Meteorites are small chunks of rock or metal that are leftovers of broken comets. They are called meteors while falling through the atmosphere and appearing as streak of light. But those meteors that fall on the earth surface are called meteorites.

Question 12.
What are phases of moon?
Answer:
The shape of the bright part of the moon changes slightly every day. These are called phases of moon.

Question 13.
What is an artificial satellite?
Answer:
Artificial Satellite. It is an object which is made to revolve around the earth or any object.

Question 14.
Write two uses of artificial satellites.
Answer:
Uses of Artificial Satellites. Artificial satellites are used for long-distance communication, research, remote sensing and defence.

Question 15.
Which planet has maximum of satellites?
Answer:
Jupiter.

Question 16.
Why is Pole star stationary?
Answer:
It is because pole star is situated on the axis of the earth.

Question 17.
Which is natural satellite of the earth?
Answer:
Moon.

Question 18.
Why can’t Moon surface be used for communication?
Answer:
It is because moon has no atmosphere.

Question 19.
Which is the biggest planet of the solar system?
Answer:
Jupiter.

Question 20.
Which is the nearest planet of the earth?
Answer:
Mars.

Question 21.
In which part of the sky and at what time of the year are the following constellations seen? Scorpio, Great Bear, Pole Star and the Orion.
Answer:
1. Scorpio is visible in summer.
2. Great bear (Saptarishi) is visible in autumn.

Pole star is visible in north throughout the year.
Orion (Vyadha) is visible in winter in southern sky only.

Question 22.
When was Halley’s comet last seen?
Answer:
In 1986.

Question 23.
Name the nearest and the farthest planet from the sun.
Answer:
The nearest planet from the sun is Mercury and the farthest planet is Neptune.

Short Answer Type Questions

Question 1.
How can you identify Ursa Major?
Answer:
Identification of Ursa Major. It is a group of seven bright stars. It appears like a large ladle or a question mark. The two stars marked 1 and 2 at the top of the ladle are called Pointers, as the line joining them points towards the polar star.

Question 2.
What are planets? How many planets are there in the solar system? Name them.
Answer:
Planets. The bright objects in the night sky which don’t twinkle like the stars and appear to change their positions with respect to the stars are called planets. In the solar system, there are nine planets. These are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Pluto and Neptune.

Question 3.
Give three points of difference between a star and planet.
Answer:
Differences between star and planet.

Star	Planet
1. They are very hot.	1. They are not very hot.
2. They emit their own heat and light.	2. They reflect the sun’s energy falling over them.
3. They twinkle.	3. They don’t twinkle.
4. They are dot-shaped.	4. They are disc-shaped.
5. They travel in the sky from East to West.	5. They travel in sky around the sun from West to East.

Question 4.
Why is life possible of the earth?
Answer:
The earth has sufficient oxygen and water necessary for life. The temperature on earth is suitable for the existence of life. Also there is an ozone layer around earth which prevents the habitants from the harmful solar radiations. Therefore, all the conditions for the evolution of life are fulfilled on the earth.

Question 5.
Do all the stars of a constellation lie really close together?
Answer:
The various stars forming a constellation are rarely close to each other in space. The stars are in the same direction but at quite different distances from us. They appear to our eye was close together, although they are not really so.

Question 6.
Name the planets which can be identified with naked eye.
Answer:
Besides our own earth, we can identify only five other planets with naked eye. These planets are Mercury, Venus, Mars, Jupiter and Saturn.

Question 7.
What is the solar system? Name the planets situated between the sun and the earth.
Answer:
Solar System. The sun and its family i.e. planets, satellites, asteroids, comets, etc. is called as solar system. The sun is at the centre of the solar system and all members of the solar system are revolving around the sun in elliptical paths, called orbits. The planets situated between the sun and the earth are Mercury and Venus.

Question 8.
What is pole star and why is it important?
Answer:
Pole Star. All the stars except one, appear to be shifting their positions in the sky. There is only one star called pole star, which does not shift its position. It is lying in North above the north pole on the axis of rotation of the earth. It is used as a direction finder by sailors and those working in, offshore drilling operations.

Question 9.
Differentiate between a star and a shooting star.
Answer:
Differences between a star and a shooting star :

Star	Shooting Star
1. A star is made up of hot gases such as hydrogen and helium.	1. A shooting star is made up of rock and metal particles.
2. A star emits light due to the nuclear reaction taking place in it.	2. A shooting star emits light due to the heat produced by friction on entering the atmosphere.
3. The size of a star is very big.	3. The size of a shooting star is very small. It may be as small as a dust particle.

Question 10.
What are meteors or the shooting stars?
Answer:
Meteors or the Shooting Stars. You must have seen certain objects which appear to fall from the sky leaving a streak of light. They are also called shooting stars. Word ‘STAR’ is in fact misleading since they are neither themselves stars nor in any way connected with stars. These are pieces of rock floating in space.

When these floating rocks enter the earth’s atmosphere, they experience a lot of friction of air and get burnt. They appear as a ball of fire falling towards earth emitting intense light. Most of these burn up in atmosphere. When a meteor is very large, it does not burn up completely and reaches the earth. This piece reaching the earth and sea is called Meteorite.

Question 11.
Represent Solar system in a tabular form.
Answer:
Solar system can be represented as
PSEB 8th Class Science Solutions Chapter 17 Stars and the Solar System 6

Question 12.
What is light year? How is it expressed in meters.
Answer:
Light year. We know that light travels nearly a distance of 3 × 10⁸ m in one second or 3,00,000 km in one second. Light year is the distance travelled by light in
1 year or in 365\(\frac{1}{4}\) days.
∴1 light year = 365 \(\frac{1}{4}\) × 24 × 60 × 60 × 3 × 10⁸ m/s
or 1 Light year = 9.46 × 10¹⁵ m

Question 13.
Why do the heavenly bodies seem to move from east to west?
Answer:
The heavenly bodies seem to be moving from east to west because earth rotates on its imaginary axis from west to east whereas it appears to us that earth is stationary. That is why various heavenly bodies appear to us moving from east to west. Earth completes one round on its axis in 24 hours.

Question 14.
Define the following terms :
1. Planet
2. Satellite
3. Period of rotation.
Answer:
1. Planet. The celestial bodies which revolve around the sun are called planets, e.g., Mercury, Earth and Venus.

2. Satellite. The celestial bodies which revolve around the planets are called satellites. Moon is a satellite of earth. Some other bodies also have satellites.

3. Period of rotation. The time taken by a planet to complete one rotation on its axis is called period of rotation.

Question 15.
Which is the brightest among all the planets and why?
Answer:
Venus is the brightest planet among all the planets. The bright appearance of Venus is due to its cloudy atmosphere, which reflects almost three-fourth of the sunlight that falls on it.

Question 16.
There is very much difference between the temperatures of Mercury and Venus planets, while there is not so on the earth and the Mars planets. Why?
Answer:
Mercury and Venus are the nearest neighbours of the sun. There is no thick atmospheric cover around them that can work like a heat cover. But these planets are so nearest to the sun that they cannot save themselves from the sunlight and are heated very much. They become most coolest after the sunset.

Only the Earth and Mars are such planets where there is a balance between the atmospheric cover and their distance from the sun. Therefore, there is not much difference in the day and night temperatures of both the planets due to this balance.

Question 17.
Why are the Mercury and the Venus known as morning or evening stars?
Answer:
The Mercury and the Venus are known as morning or evening stars because both can be seen near the horizon immediately before the sunrise and after the sunset. At this time, these appear like the brightest star.

Question 18.
What are the conditions favouring life to flourish on earth?
Answer:
Following are the conditions that favour life to flourish on earth :

Oxygen is present in the atmosphere of the earth which is necessary for respiration for all the organisms.
Presence of water for the biological process on the earth.
Due to proper distance of the earth from the sun, there is proper temperature on the earth.
Presence of protective ozone layer around the earth which protects us from the ultraviolet radiations of the Sun.

Long Answer Type Questions

Question 1.
What is a solar system?
Answer:
Solar System: Solar system consists of the Sun, a large number of asteroids between Mars and Jupiter. There are large number of comets or shooting stars which move in highly elliptical paths. The planet nearest to the sun is Mercury followed by Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune. Whereas mercury is the smallest planet, Jupiter is the largest one.
PSEB 8th Class Science Solutions Chapter 17 Stars and the Solar System 7
The planets rotate about the sun in elliptical path as well as spin about their own axis [Fig. (6)]. The nearest star to our solar system is Alpha Centauri and is about 4.3 light-years away from us. Brightest star Sirius is about 8.7 light-year from us.

Fig. (a) shows the motion of different planets around the sun (not to the scale). Shape of solar system resembles an inverted saucer with all planets. Sun dominates the solar system and accounts for 99.9% of total matter of the whole system. The sun is the source of all the energy in solar system. Earth receives almost all the energy from the sun.

Question 2.
What is meant by Uttrayan and Dakshinayan?
Answer:
Uttrayan and Dakshinayan. We generally say that the Sun rises in the east and sets in the west. This is only partially correct because the position of rising sun changes every day. Let us perform a time-consuming experiment to stress our point. Note down the direction of rising sun on the sky.

Repeat the observation every week. A continuous change will be observed. From summer solstice (around June 21), the point of the sun shifts towards south. The sun is said to be in dakshinayan (moving south). This continues till winter (around December 22). After this sunrise changes its direction and stars move towards north. Now it is said to be in Uttaryan (moving north). Only on March 21 and September 23, the sunrise in the east and sets in the west.

Question 3.
What are terrestrial and Jovian Planets?
Answer:
Terrestrial planets. Four planets near to the Sun i.e. mercury, venus, earth and mars are called terrestrial planets. Their structure is similar to that of the earth. These are small planets and have a thin atmosphere on them.
Jovian planets are larger in size than terrestrial planets.

These planets are made of mainly hydrogen and helium. These planets, namely Jupiter, Saturn and Neptune are so-called because their structure is similar to Jupiter. They have a number of moons around them and some have rings around them. Their temperature, gravity etc. are such that life can never be possible on them.

Question 4.
Write a short note on ‘Comets’.
Answer:
Comets: Comets are heavenly bodies which revolve around the Sun in highly elliptical path. Comets appear in the sky as a ball of fire with a tail. Tail always points away from the sun. Lesser the distance it has from the sun, longer is the tail. Comets are composed of rock-like material surrounded by large masses of easily vaporised substances like water, ammonia, methane etc. When comets approach the sun, some of its material is vaporised due to heat of the sun. Light of the sun exerts pressure on these vapours and force them away Tail is longest and from the comet in the form of a tail.
PSEB 8th Class Science Solutions Chapter 17 Stars and the Solar System 8

Question 5.
Write various uses of artificial satellites.
Answer:
Uses of Artificial Satellites. Various uses of artificial satellites are as follows :

They can be used to forecast weather.
They facilitate radio and television programme transmission.
Artificial satellites enable long-distance telephone communication.
They help to locate mineral and metal deposits.
Artificial satellites fitted with telescopes and software programmes gather and process data on space phenomena, thus enhancing our knowledge and understanding of the universe.