Question

Give a few applications of Faraday's law of induction in daily life.

Answer 1

First Law: Whenever the amount of magnetic flux linked with a circuit changes, an e.m.f is induced in the circuit. The induced e.m.f lasts so long as the change in magnetic flux continues.
Second Law: The magnitude of e.m.f induced in a circuit is directly proportional to the rate of change of magnetic flux linked with the circuit.

Complete step by step answer:
Some of the important applications of Faraday's law of induction are:
Electro-magnetic damping: This is used in designing deadbeat galvanometers.
When a steady current is passed through the coil of a galvanometer, it is deflected. Normally, the coil oscillates about its equilibrium position for some time before coming to rest.
To avoid delay due to these oscillations, the coil is wound over a metallic frame. As the coil is deflected, eddy currents set up in the metallic frame oppose its motion.
Therefore, the coil attains its equilibrium position almost instantly. Thus the motion of the coil is damped. This is called electromagnetic damping.
Induction Furnace: It makes use of the heating effect of eddy currents. The substance to be heated/melted is placed in a high frequency magnetic field. The large eddy currents developed in the substance produce so much heat that it melts. Such an arrangement is called an induction furnace. It is used for extracting a metal from its ore and also in the preparation of certain alloys.
Electro-magnetic Brakes: They are used in controlling the speed electric trains. A strong magnetic field is allied to a metallic drum rotating with the axle connecting the wheels. Large eddy currents set up in the rotating dum oppose the motion of the drum and tend to stop the train.
Induction Motor: An induction motor or A.C, motor is another important application of eddy currents. A rotating magnetic field produces strong eddy currents in a rotor, which starts rotating in the direction of the rotating magnetic field.
In speedometers of automobiles and energy metres.

Note: Eddy current is induced due to change in magnetic flux in metallic sheet. So in application of Faraday's law of induction we have discussed eddy currents.