Question

The stopping potential of the photoelectrons, from a photo cell is

• A. directly proportional to intensity of incident light
• B. directly proportional to frequency of incident light
• C. inversely proportional to frequency of incident light
• D. Inversely proportional to intensity of incident light

Answer 1

Answer: (B)

directly proportional to frequency of incident light

Answer 2

The stopping potential of photoelectrons is potential needed to stop the electrons from reaching the collector depends only on the frequency of incident radiation. It is directly proportional to it. This is because, more the frequency of incident light, more will be the energy of the photons incident photons. $\quad(E=h v)$ Thus, more will be the energy (kinetic) acquired the electrons.
More the kinetic energy of emitted electrons, higher is the potential needed to stop them (stopping potential).