Dual Nature Of Light Question 267

Question: When a point source of light is at a distance of one metre from a photo cell, the cut off voltage is found to be V. If the same source is placed at 2 m distance from photo cell, the cut off voltage will be

Options:

A) V

B) V/2

C) V/4

D) $ V/\sqrt{2} $

Show Answer

Answer:

Correct Answer: A

Solution:

By changing distance of source, photoelectric current changes. But there is no change in stopping potential.