21.A spring of constant K is cut into parts of length in the ration 1 : 2. The spring constant of larger one is

22.Two bars A and B of circular cross-section and of same volume and made of the same material are subjected to tension. If the diameter of A is half that of B and if the force applied to both the rods is the same and it is in the elastic limit, the ratio of extension of A to that of B will be

23.What happen to the elastic property of a substance after annealing (cooling slowly after heating)?

24.Two wires of the same material and radius but having length in the ratio of 1 : 2 are stretched with the same force. The ratio of the work done in two cases is

25.Two wires of the same material and length are stretched by the same force. Their masses are in the ratio 3:2, their elongations are in the ratio: