In the system shown in Fig the friction coefficient between ground and bigger block is `mu` There is no friction between both the block .The string connecting both the block is light all three pulley are light and frictionless Then the minimum limiting value of `mu` so that the system remain in equilibrium , is

Options

A. `(1)/(2)`
B. `(1)/(3)`
C. `(2)/(3)`
D. `(3)/(2)`

Answer

C

Explanation

In equilibrium

`T = mg ,N = 3 mg and f= 2T = 2 mg`
In limiting case `flt f_(max)`
`2mg lt mu N`
`rArr 2mg le 3 mu mg rArr mu ge (2)/(3)`