Introduction of project-> How to make a LDR project with transistor

In this module, we will learn the interfacing of LDR with transistor.

LDR is a Light dependent resistor, also known as photoresistor. This is the light sensitive device which is used to indicate the presence and absence of light or measure the intensity of light. LDR have a variable resistance that changes with the amount of light intensity fall on it. When the LDR is placed in dark means no light then the resistance will increase and when it is placed in light then the resistance will decrease.

As we have already discussed about transistors in the previous lessons,Transistors are of two types NPN and PNP. So, we will be using both the transistors to make this circuit with LDR.