A photocell is illuminated by a small bright source placed 1 m away. When the same source of light is placed 2 m away, the number of electrons emitted by photocathode are reduced by a factor of
A. 1/8
B. 1/16
C. 1/2
D. 1/4
Answer:D
A photocell is illuminated by a small bright source placed 1 m away. When the same source of light is placed 2 m away, the number of electrons emitted by photocathode are reduced by a factor of
A. 1/8 B. 1/16 C. 1/2 D. 1/4