Light dependent resistors are

Solution (By Examveda Team)

Light-dependent resistors (LDRs) are special resistors whose resistance changes depending on the amount of light shining on them.

To understand why, we need to know a bit about semiconductors.

Semiconductors are materials that are neither good conductors (like metals) nor good insulators (like rubber). Their conductivity can be changed.

Intrinsic semiconductors have a moderate number of charge carriers (electrons and holes) that allow them to conduct electricity, but this is relatively low.

Lightly doped semiconductors have a small amount of impurities added to increase their conductivity. This makes them slightly better at conducting.

Highly doped semiconductors have a large amount of impurities added, making them very good conductors.

LDRs work because light creates more charge carriers in the semiconductor material. More carriers mean better conductivity, and thus lower resistance. To make this effect strong, LDRs are usually made from lightly doped semiconductors. The small amount of doping provides the basis for a significant change in resistance when light strikes the material.

Therefore, the correct answer is C: Lightly doped semiconductor.