Question

class 12th only!


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.

(IIT) ​

Answer 1

Answer:

Light or visible light is electromagnetic radiation within the portion of the electromagnetic spectrum that can be perceived by the human eye.Visible light is usually defined as having wavelengths in the range of 400–700 nm, or 4.00 × 10−7 to 7.00 × 10−7 m, between the infrared (with longer wavelengths) and the ultraviolet (with shorter wavelengths).

Answer 2

Intensity of photons ↑, no. of electron t

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 = I = 18 x 0.2

but,

0.6 = 2mA

So, the answers are option (C) & (D).