CBSE Class 12-science Answered

If LED is emitting light , then state of output is 1 else 0 .

If switch A or B is closed then the respective input state is 1 else 0 .

if bothe the switches are closed , then LED is shorted and LED will not emit light.

if either one of the switch is open or both the switch is open then current is passing through LED

and LED will emit light .

Truth table is given below

A	B
1	1	0
1	0	1
0	1	1
0	0	1

From above truth table , we see that Boolean operation represented by the circuit is NAND