Question

The change in magnetic field lines in a coil is the cause of induced electric current in it. Name the underlying phenomenon.

Answer 1

Electromagnetic induction:

1. When the magnetic flux through a coil changes, there is a change in the potential difference through it, this is known as induced EMF.
2. The current produced due to this induced EMF is known as electromagnetic induction.
3. According to the Lenz law, when a conductor is placed inside a magnetic field, an EMF is induced in it.
4. The current induced in a circuit due to a change in the magnetic field is directed to oppose the change in magnetic flux.
5. The induced EMF is given by the formula $\epsilon =-N\frac{d\varphi }{dt}$, where $N$ is the number of turns of a coil and $\frac{d\varphi }{dt}$ is the rate of change in magnetic flux.

Hence, the change in magnetic field lines in a coil is the cause of induced electric current in it is known as electromagnetic induction.