The magnitude of stopping potential is given by

The frequency of light is given by

The work function of metal is given by

Where,=Planck’s constant; =Wavelength of light; =Threshold wavelength; =Threshold frequency; =Velocity of light and =charge on electron

Put equation (2) and equation (3) in equation (1), we get

Now, if the frequency of light is doubled, the stopping potential will be

To compare equation (4) and (5), we need to multiply 2 in equation (4) on both sides, we get

Now, comparing equation (5) and equation (6),

Therefore, the stopping potential becomes more than double when the frequency of light is doubled.