This simple circuit will demonstrate the automatic light on-off circuit. In actual circuit we use the LDR(light dependent resistor) in place of the Resistor connected across the output led ( yellow colour ).
LDR has a resistance ranges from (33 - 33k)ohms i.e when light falls on the LDR the resistance of the LDR decreases upto 33ohms otherwise increases upto 33k ohms when we increase the darkness.
TRY IT YOURSELF: try to increase and decrease the Resistor connected across the output led ( yellow colour ) and observe the result yourself.
