The pulley arrangements shown in the figure are identical, the mass...

The pulley arrangements shown in the figure are identical, the mass of the rope being negligible. In case (a) mass \( m \) is lifted by attaching a mass of \( 2 \mathrm{~m} \) to the other end of the rope. In case (b) the mass \( \mathrm{m} \) is lifted by pulling the other end of the rope with a constant downward force \( F=2 \mathrm{mg} \), where \( g \) is the acceleration due to gravity. The acceleration of mass \( \mathrm{m} \) in case (a) is :-
(a)
(b)
(1) Zero
(2) More than that in case (b)
(3) Less than that in case (b)
(4) Equal to that in case (b)