This PSEB 10th Class Science Notes Chapter 13 Magnetic Effects of Electric Current will help you in revision during exams.
PSEB 10th Class Science Notes Chapter 13 Magnetic Effects of Electric Current
→ A current-carrying conductor behaves like a magnet. Magnet and electricity are related to each other.
→ Hans Christian Oersted did remarkable work to make us understand electromagnetism.
→ That end of freely suspended magnet which points towards north direction is called North Seeking or the North Pole and the other end which points towards south direction is called South Seeking or the South Pole.
→ Like poles repel each other while unlike poles attract each other.
→ The field or area around a magnet in which its effect or force can be experienced is called the magnetic field of the magnet.
→ The direction of magnetic lines of force inside the magnet is from the south pole to the north pole while outside the magnet it is from the north pole to the south pole. Therefore, magnetic lines are closed curves.
→ Two magnetic lines of force never intersect each other.
→ On passing a current through a metallic conductor, the magnetic field is produced around it.
→ The magnetic field produced all around it is inversely proportional to its distance.
→ The magnetic field at a point inside the magnetic field produced due to the current flowing through a conductor is proportional to the current flowing through the conductor.
→ A coil consisting of a cylindrical-shaped coil having closely packed turns of insulated copper wire is called a solenoid.
→ Inside a solenoid, magnetic lines of force are just like parallel straight lines. The magnetic field is the same at all points inside the solenoid.
→ The force acting in a conductor is in the direction of current and perpendicular to the direction of the magnetic field. This is called Fleming’s left-hand rule.
→ Electric motor, electric generator, loudspeaker, microphone, and electric meter are related with current-carrying conductor and magnetic field.
→ Production of the magnetic fields is necessary for our heart and brain.
→ MRI is important in medical treatment.
→ The electric motor is a device in which electrical energy is transformed into mechanical energy.
→ Electric motors find their use in electric fans, refrigerators, electric mixers, washing machines, computers, MP3 players, etc.
→ In electric motors, a rectangular coil of insulated wire is placed in between two poles.
→ That device that alternately changes the flow of current is called an AC motor.
→ Soft iron core and coil together form an armature. This increases the power of the motor.
→ Faraday discovered how the moving magnet can be used in producing current.
→ A galvanometer is an instrument that is used to detect the presence of current in a circuit.
→ That process by which the change in the magnetic field of a conductor produces a current in another conductor is called electromagnetic induction.
→ When the direction of motion of a coil is perpendicular to the direction of the magnetic field, then the induced electric current in the coil becomes maximum.
→ In electric generators, mechanical energy is used to rotate a conductor placed in a magnetic field as a result of which current is produced.
→ The device used to produce electricity is called an A.C. generator.
→ Electromagnet: A soft iron piece placed inside an insulated conducting coil becomes an electromagnet on passing current.
→ Magnetic Field: The field around a magnet in which its effect can be felt.
→ Solenoid: A coil made by winding a conducting wire having a large number of closed turns.
→ Iron Core: The soft iron rod placed inside the solenoid is called the iron core.
→ Snow Rule: When a wire placed above a magnetic needle carries current from the south direction to the north direction then the north pole (N-pole) of the magnetic needle gets deflected westward.
→ Electromagnetic Induction: Due to change in the magnetic field the current produced in the neighboring coil is called electromagnetic induction.
→ Electric Energy: The capacity for doing work by an electric current is known as electric energy.
→ Electric Power: The rate at which electric energy is consumed in a conductor is called electric power.
→ Electric Generator: The instrument which produces electric current is called an electric generator.
→ Alternating Current (A.C): That current which continuously changes direction alternately is called alternating current.
→ Direct Current (D.C.): That current which has the same direction always is called direct current (D.C.)
→ Short Circuit: When the live wire comes in direct contact with the neutral wire due to damaged wiring or uncovered wire, the resistance of the circuit becomes zero, and the current flowing through the circuit increases suddenly. This is called short-circuiting.
→ Fuse (Safety Fuse): A wire of low melting point connected in an electric circuit is called a fuse.
→ Electric Meter: A device that is connected to an electric circuit to measure electric energy being used is called an electric meter.
→ Electric Shock: When any part of the human body touches any point of the unsheathed (without insulation) circuit having high potential, shock is experienced which is known as electric shock.
→ Overloading: If the current through a circuit is more than the maximum prescribed limit then the wires become hot and may catch fire. It is called overloading.
→ Right Hand Thumb Rule: If we imagine that current is passing through a conductor held in your right hand such that the thumb points in the direction of current then the curling fingers would represent the direction of the magnetic field.
→ Flemming’s Left-Hand Rule: Stretch your left hand in such a way that the first central fingers are mutually perpendicular to each other, then if the first finger points in the direction of the magnetic field, the central finger in the direction of current then the thumb points in the direction of motion of the conductor.
→ Earthing: The joining of metallic frame of the electric appliance of high power with the earth wire of domestic circuit is called earthing.