Draw a schematic diagram of nuclear power plant.

A spring of spring constant $\mathrm{K}= 4\mathrm{x}{10}^3\mathrm{N}/\mathrm{m}$ is compressed by $2 \mathrm{cm}$, then determine the potential energy stored in spring. 

Ratio of potential energies of body A and body B will be

Give reasons for the following: After winding the spring of watch, the hands of the watch move.