What characteristic of an LDR changes with light intensity?

A Light Dependent Resistor (LDR) is a type of resistor that changes its resistance based on the amount of light it is exposed to. Specifically, as light intensity increases, the resistance of the LDR decreases. This characteristic makes LDRs useful in various applications, such as light sensing circuits or in devices that automatically adjust to changing light conditions.

When light falls on the LDR, it causes an increase in the number of charge carriers (typically electrons) within the semiconductor material of the LDR, which in turn lowers its resistance. In dim light or darkness, the resistance of the LDR is high, and as the light intensity increases, the resistance drops significantly. This conductive behavior created by the change in light intensity allows LDRs to be effectively integrated into circuits for automatic brightness controls, light alarms, and other similar applications.