What happens to the resistance of a light-dependent resistor (LDR) when light increases?

As the light intensity increases, the resistance of a light-dependent resistor (LDR) decreases. LDRs are constructed from materials that exhibit photoconductive properties, meaning they can change their electrical resistance based on the amount of light they are exposed to. When more light hits the LDR, it energizes the charge carriers in the material, allowing them to move more freely. This results in a reduction in resistance.

In contrast, when light decreases, the resistance of the LDR increases because there are fewer charge carriers available to conduct electricity. Thus, the resistance of an LDR is inversely related to the light intensity: more light corresponds to lower resistance. This property makes LDRs useful in applications such as light-sensing circuits and automatic lighting systems.