Question

A copper ring is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring. Acceleration of the falling magnet is

• A. Greater than $g$
• B. Less than $g$
• C. equal to $g$
• D. None of these

Answer 1

The correct option is B

Less than $g$

Explanation

1. When bar magnet freely falling through conducting copper loop, it changes the magnetic flux passing through the loop.
2. Therefore, emf. will be induced in the opposite direction of motion of bar magnet as per Lenz law.
3. Due to force of oppositely induced emf., we conclude that the acceleration of the falling magnet is less than $g$.

So, the correct option is (B) less than $g$.