Photo emissive cells are based on the principle of photoelectric effect and converts light into electricity
Electrons are emitted from the cathode when it is illuminated.
These emitted electrons are attracted by the anode and a current will be generated which is measured by a galvanometer present in the circuit.
The current that is produced depends on two factors:-
Intensity of incident radiation.
Potential difference across cathode and anode.
Applications of photoelectric cells:-
1.They are used in counting devices.
2.They are used in fire and burglar alarms.