NEET Physics Atoms Questions Solved

The time of revolution of an electron around a nucleus of charge Ze in nth Bohr orbit is directly proportional to

(a) n             (b) $\frac{{\mathrm{n}}^2}{{\mathrm{Z}}^2}$
(c) $\frac{{\mathrm{n}}^2}{\mathrm{Z}}$          (d) $\frac{\mathrm{Z}}{\mathrm{n}}$