Question

Which device works on the principle of mutual induction?

Answer 1

1. Mutual inductance is a phenomenon where a current is produced in the secondary coil due to a change in current in the primary coil. The coils are kept in close vicinity to each other.
2. This happens in accordance with Faraday's law, which states that a varying magnetic flux through a circuit will produce an emf and hence a current. In this case, the coils produce the magnetic field and AC current flowing through the coils produces a varying magnetic flux.
3. A device that works on the principle of mutual induction is the transformer. It is a device that transfers electrical energy from one coil to another and in the process changes the voltage/current according to requirement.
4. The input voltage is put in the primary coil and the induced voltage forms in the secondary coil. The induced voltage depends on the number of turns in the primary and secondary coils.

Here, $P$ is the primary coil, $S$ is the secondary coil and the laminated cores are there to maximize the magnetic flux density within the coils.