The output, Z=A.B =A+B (Using de-Morgan theorem) This is the expression of a NOR gate. So, the logic operation carriedout by the given circuit is NOR. Alternate Method The given question can be solved using truth table, which is as given below
A
B
X
Y
Z
0
0
1
1
1
1
1
0
0
0
1
0
0
1
0
0
1
1
0
0
This truth table is similar to that of a NOR gate.