Three charges $$-\mathrm{q}, \mathrm{Q}$$ and $$-\mathrm{q}$$ are placed at equal distances on a straight line. If the total potential energy of the system of three charges is zero then the ratio $$\frac{Q}{q}$$ is

In photoelectric effect, the photo current

If the potential difference across a capacitor is increased from $$5 \mathrm{~V}$$ to $$15 \mathrm{~V}$$, then the ratio of final energy to initial energy stored in the capacitor is

A body of mass 'm' and radius of gyration 'K' has an angular momentum 'L'. Then its angular velocity is