Q. Assertion: A photocell is called an electric eye.
Reason: When light is incident on some semiconductor its electrical resistance is reduced.

 2089  223 AIIMSAIIMS 2009Semiconductor Electronics: Materials Devices and Simple Circuits Report Error

Solution:

Photo-conductive cell is based on the principle that when light is incident on some? semiconductor, its electrical resistance is reduced. Such cells are used in solar batteries. Whereas photocell is used in electrolyte for giving theft warning in banks treasuries, etc., when the thief throws torch light on the cash box, the light is incident on a photocell placed there and a bell at some particular place rings.