Question

Describe the construction of photoelectric cell.

Answer 1

Photoelectric cell consists of highly evacuated or gas filled glass tube, an emitter and a collector. The light enters through a quartz window and falls on the semicylindrical cathode $C$ coated with photosensitive metal. The anode is in the form of straight wire of platinum or nickel, co-axial with cathode. If the cell is required to respond to the visible part of the spectrum, the cathode is coated with potassium or rubidium and the quartz window is replaced by glass.