In Fig.7.125, coefficient of friction between `m_(1)` and `m_(2)` is `mu` and that between `m_(1)` and the wall is zero. A force F is pressing the system against the wall. Minimum value of force required to hold the system in equilibrium is :

Options

A. `mu_(1)g`
B. `mu_(1)g`
C. `mu(m_(1)+m_(2))g`
D. system cannot be held in equilibrium

Answer

D

Explanation

No force in vertical direction on `m_(1)` as wall is smooth .