Question

A point source of light is used in an experiment of photoelectric effects. If the distance between the source and the photo-electric surface is doubled, which of the following may result ?

• A. Stopping potential will be halved
• B. Photoelectric current will decrease.
• C. Maximum kinetic energy of photo-electrons will decrease.
• D. Stopping potential will increase slightly.

Answer 1

The correct option is B Photoelectric current will decrease.

If the distance between source and surface doubled, the intensity of light falling on surface becomes one-fourth.

So as the intensity is decreasing, the photoelectric current will decrease.

Maximum kinetic energy depends only on frequency of incident light.