List of practice Questions

The two wires A and B of the same material have their lengths in the ratio 1 : 2 and their diameters in the ratio 2 : 1. If they are stretched with the same force, the ratio of the increase in the length of A to that of B will be:
A light ladder is supported on a rough floor and leans against a smooth wall, touching the wall at height \( h \) above the floor. A man climbs up the ladder until the base of the ladder is on the verge of slipping. The coefficient of static friction between the foot of the ladder and the floor is \( \mu \). The horizontal distance moved by the man is:
Calculate the number density of free carriers in silver, assuming that each atom contributes one carrier. The density of silver is \( 10.5 \times 10^3 \, \text{kg/m}^3 \) and the atomic weight is 107.8.
The source of energy in the Sun is: