Question

If intensity of incident radiation in a photocell is increased, the stopping potential

• A. first increases and then decreases.
• B. remains unchanged.
• C. decreases.
• D. increases.

Hint:

The stopping potential depends on the frequency of the incident radiation, not its intensity. Intensity increases the number of emitted electrons, but not their maximum energy.

Answer 1

The Correct Option is B

Step 1: Understanding the photoelectric effect.
In the photoelectric effect, the stopping potential is the potential required to stop the most energetic photoelectrons emitted from the photocell. The stopping potential depends on the frequency of the incident light but not on the intensity of the light.
Step 2: Effect of intensity.
Increasing the intensity of the incident radiation increases the number of photoelectrons emitted but does not affect their maximum kinetic energy. Since the stopping potential is determined by the maximum kinetic energy of the photoelectrons, it remains unchanged with increasing intensity.
Step 3: Conclusion.
Thus, the stopping potential remains unchanged when the intensity of incident radiation is increased, which corresponds to option (B).