Write the truth table for the circuits given in figure, consisting of NOR gates only. Identify the logic operation ( OR, AND, NOT ) performed by the two circuits.

Explanation

B is the output of OR gate and input of NOT gate. So, the gate resembles to NOT gates or is input and Y is output .

C is the output of OR gate 1 and input a NOT gate 1, D is the output of OR gate 2 and input of NOT gate 2,F is the output of NOT gate1, f is the output of NOT gate 2.
G is the output of OR gate 3 and inputof NOT gate 3. The truth table resembles to AND gate as A and B inputs and Y is output.

This operation is AND gate.