What happens to the resistance of a photoresistor when the intensity of incident light increases?
The resistance decreases
A photoresistor (LDR, light-dependent resistor) is made of a photoconductive semiconductor such as cadmium sulphide (CdS).
When light falls on it, photons with enough energy free electrons from the valence band into the conduction band, creating electron–hole pairs.
More light means more free charge carriers, so conductivity rises and resistance falls — from megaohms in darkness to a few hundred ohms in bright light.
The resistance therefore does not increase or stay constant, and it never reaches zero, because the material always keeps some finite resistance.
Hence, the answer is The resistance decreases.
Important Questions from Opto Electronic Components
The full form of LED is:
An optical fiber is a cylindrical dielectric waveguide that transmits _____ along its axis.
Which among the following is used as receiver in fiber optic communication?
Which one of the following is a photo-voltaic module?
Pulses of Light are used in _____ for communication system to transmit information.
