Three equal weights A, B, C of mass 2 kg each are hanging on a string passing over a fixed frictionless pulley as shown in the figure. The tension in the string connecting weights, B and C is:

For A: T -2g = 2a-----(i)For B : T1+2g -T = -2a-----(ii)For C : 2g-T1 = 2a----(iii)Adding equations (i) and (ii),we get T1 = 4a-----(iv)From equations (iii) and (iv)2g -4a = 2aa = g3----(v)From equations (iv) and (v),T1 = 4 ×g3 = 13 N