Question

A bar magnet is moved between two coaxial coils A and B as shown in figure. The end planes of two coils facing the magnet due to induction will behave:

• A. north pole in both the coils A and B
• B. south pole in both the coils A and B
• C. North pole in coils A and North pole in coil B
• D. south pole in coil A and north pole in coil B

Answer 1

The correct option is B. south pole in both the coils A and B

$\text{Given}$: A bar magnet is moved between two coaxial coils.

$\text{To find}$: The end planes of two coils facing the magnet due to induction will behave?

$\text{Solution}$:

1. According to Lenz’s law:- The polarity of the induced emf is such that it tends to produce induced current in such a direction that it opposes the change in magnetic flux that produced it.

2. According to Lenz’s law, the end of coil A facing the S-pole of the magnet will behave as the south pole which will try to repel the S-pole of the magnet.

3. When the N-pole of the magnet moves away from coil B then according to Lenz’s law, Southpole is developed at the end of the coil B facing the N-pole of the magnet.

$\text{Hence B is correct option}$.