A mass of `2kg` is suspended with thread `AB` (figure) Thread `CD` of the same type is attached to the other end of `2kg` mass. Lower thread is pulled gradually, harder and harder in the downward gradually, harder and harder in the downward direction so as to apply force on `AB`. which of the threads will break and why?

Explanation

The thread AB will break earlier than the thread CD. This is because force acting on thread CD = applied force and force acting on thread AB = (applied force + weight of 2 kg mass). Hence, force acting on thread AB is larger than the force on thread CD.