(a) A acts as the two inputs of the NOR gate and Y is the output, as shown in the
The truth table for the same is given as:
| A |
 |
| 0 |
1 |
| 1 |
0 |
This is the truth table of a NOT gate. Hence, this circuit functions as a NOT gate. (b) A and B are the inputs and Y is the output of the given circuit. By using the result obtained in solution (a), we can infer that the outputs of the first two NOR gates are
as shown in the following figure.
| A |
B |
Y (=A!B) |
| 0 |
0 |
0 |
| 0 |
1 |
0 |
| 1 |
0 |
0 |
| 1 |
1 |
1 |
This is the truth table of an AND gate. Hence, this circuit functions as an AND gate.
