In the pulley arrangement shown in figure, the pulley \( P_{2} \) i...

In the pulley arrangement shown in figure, the pulley \( P_{2} \) is movable. Assuming the coefficient of friction between \( \mathrm{m} \) and surface to be \( \mu \), the minimum value of \( M \) for which \( m \) is at rest is
(1) \( M=\frac{\mu m}{2} \)
(2) \( m=\frac{\mu M}{2} \)
(3) \( M=\frac{m}{2 \mu} \)
(4) \( m=\frac{M}{2 \mu} \)