Question

A vertical bar magnet is dropped from position on the axis of a fixed metallic coil as shown i fig I. In fig. II the magnet is fixed and horizontal coil is dropped. The acceleration of the magnet and coil are $a_1$ and $a_2$ respectively then

• A. $a_1>g,a_2>g$
• B. $a_1>g,a_2<g$
• C. $a_1<g,a_2<g$
• D. $a_1<g,a_2>g$

Answer 1

Answer: (C)

$a_1<g,a_2<g$

Solution

Fig 1

As bar magnet will fall , an induced current is developed in coil which will oppose the motion of magnet.

Therefore a < g

Fig 2

As coil will fall on bar magnet , again induced current will develop in coil which will oppose its movement and prevent it from falling.

Therefore a , g

The correct option is C