Question

when a monochromatic point source of light is at a distance of 0.2m from a photoelectric cell, the cut off violage and the saturation current are respectively 0.6V and 18.0mA. if the same source is placed 0.6m away from th photoelectric cell, then comment about its stopping potential. ​

Answer 1

Answer:

Intensity of photons ↑, no. of electron ↑

The cut off voltage does not depend on distance between cell and source.

But intensity is inversely proportional to square of it's distance.

$∴ at \: d=0.6m,$

➪Cut off voltage =0.6V

but

1s=⤵️

$18 \times ( \frac{0.2}{0.6} ) ^{2}$

$=2mA$

Answer 2

Intensity of photons ↑, no. of electron ↑

The cut off voltage does not depend on distance between cell and source.

But intensity is inversely proportional to square of it's distance.

∴$\sf{ at \: d=0.6m,}$

➪Cut off voltage =0.6V

but

1s=⤵️

$\sf{18 \times ( \frac{0.2}{0.6} ) ^{2}}$