Solution:
Stopping potential depends on the wavelength of incident radiation. It is independent of the distance
between the source and photoelectric cell. intensity of illumination varies inversely as the square of distance.
When a monochromatic point-source of light is at a distance of 0.2 m from a photo-electric cell, the
cut-off voltage and the saturation current are respectively 0.6 V and 18'0 mA. If the same source is placed 0.6 m away from the photoelectric cell, then
Stopping potential depends on the wavelength of incident radiation. It is independent of the distance
between the source and photoelectric cell. intensity of illumination varies inversely as the square of distance.