What is ldr mean?

LDR stands for Light Dependent Resistor or Light Dependent Sensor. It is a type of resistor whose resistance varies depending on the amount of light falling on it. When exposed to light, the resistance of an LDR decreases, allowing more current to flow through it. Conversely, in darkness, the resistance of an LDR increases, reducing the amount of current that can flow through it.

LDRs are commonly used in light sensing applications such as automatic street lights, camera light meters, and alarm systems. They are also used in various electronic devices and circuits that require automatic adjustment of light sensitivity.

LDRs are often used in conjunction with other components such as transistors, relays, and microcontrollers to create light-sensitive circuits that can perform specific functions based on the level of light detected. They are relatively inexpensive and easy to use, making them popular in many consumer electronics and industrial applications.