In the arrangement shown in the figure pulleys A and B are massless and the thread is inextensible. Mass of pulley C is equal to m. If friction in all the pulleys is negligible, then

FBD of Cmg−2T=mc   ……(i)If we assume acceleration of A to be 'a'upwards; by constraint equation we get:−a−a+c+a+c=0⇒a=2cand for block A:2T=mA⋅a but as mA=0⇒T=0 so we get c=g and a=2g↑