List of top Physics Questions on Capacitors and Capacitance asked in WBJEE

If the charge on a capacitor is increased by $2$ coulomb, the energy stored in it increases by $21\%$. The original charge on the capacitor is

A body of mass $40\mathrm{kg}$ is resting on a rough horizontal surface and is subjected to a force $P$, which is just enough to start the motion of the body. If ${\mu }_s=5,{\mu }_k=0.4,\mathrm{g}=10\mathrm{m}/{\mathrm{s}}^2$ and the force $P$ is continuously applied on the body, then the acceleration of the body is