Question

If the intensity of incident radiation in a photo-cell is increased, how does the stopping potential vary?

(a) Increases

(b) Remains the same

(c) Decreases

(d) Infinite

I have been asked this question in an international level competition.

My question is taken from Einstein’s Photoelectric Equation : Energy Quantum of Radiation in chapter Dual Nature of Radiation and Matter of Physics – Class 12

Answer 1

The correct choice is (b) Remains the same

To explain I would say: There is no effect on stopping potential. The intensity of incident radiation is independent of stopping potential. Therefore, even if the incident radiation in a photo-cell is increased, the stopping potential remains unchanged.