A smooth block of mass `m` is held stationary on a smooth wedge of mass `M` and inclination `theta` as shown in figure .If the system is released from rest , then the normal reaction between the block and the wedge is

Options

A. ` mg cos theta`
B. less than `mg cos theta`
C. greater than `mg cos theta`
D. may be less or greater than `m g cos theta ` depending upon whether `M` is less or greater than `m`

Answer

B

Explanation

During motion of block , `a` component of its acceleration comes in the direction of `mg cos theta` Therefore
`mg cos theta gt N`