When a tuning fork is sounded in air, the sound given by it is feeble. But when it is placed on a table top, the sound becomes much louder. The reason is :

1. amplitude of the wave
2. its prongs start vibrating rapidly
3. presence of a surrounding wave
4. large surface area of the vibrating body

Three bulbs of equal resistance are connected as shown in figure. Out of the following statements which one is correct ?

1. The current at B is greater than that at C.
2. The current at A equals the current at B.
3. The current at C is greater than that at B.
4. The current at A equals the current at C.

Assertion (A) : The direction of induced current is such that it opposes the cause which produces it.

Reason (R) : A current is induced in the coil if there is a change in the magnetic flux linked with the coil.

1. both A and R are true and R is the correct explanation of A
2. both A and R are true and R is not the correct explanation of A
3. assertion is false but reason is true
4. assertion is true but reason is false