For a photosensitive material, work function is '$W_0$' and stopping potential is 'V'. The wavelength of the incident radiation is (h=Planck's constant, c = velocity of light, e = electronic charge)

Using Einstein's photoelectric equation, the graphical representation between the kinetic energy (E) of emitted Photoelectrons and the frequency of incident radiation ($\nu$) is show correctly in figure

The force acting on the electron in hydrogen atom (Bohr's theory) is related to the principal quantum number n as

Using Bohr's atomic model, the orbital period of electron in hydrogen atom in the $n^{\text{th}}$ orbit is ($\epsilon_0$=permittivity of free space, h=Planck's constant, m = mass of electron, e = electronic charge)