Assertion : Two forces are acting on a rope lying on a smooth table as shown in figure. In moving from (A ) to (B ), tension on string decreases from (2 F ) to (F ). Reason : Situation will become in determinant, if we take it a massless string.

Step-by-step solution

Tension variation - With unequal pulls at the ends (2 F at A and F at B) on a rope on a smooth table, the internal tension must vary linearly from 2F near A down to F near B to satisfy equilibrium of each small rope element. On massless string claim - Saying the situation becomes indeterminate for a massless string is a separate fact often discussed in assertion-reason keys for this problem; both I and II are marked true, but II is not the explanation for I in standard solutions.