You are given the two circuit as shown in figure, show that the circuit (a) acts as OR gate while the circuit (b) acts as AND gets

Explanation

(a) Split the gate ,OR gate

Here,for given A and B as inputs, C is the output of OR gate and input of NOT gate 1,D the output of NOT gate 1 and input of NOT gate 2, then Y is finally output.

This is same as OR gate.So, that circuit acts as OR gate.
(b) Split the gate `:`

Here, for given A and B as inputs,C is the output of A and D is the output of B,E, is the output of OR gate and input of NOT gate 3, then Y is finally output .
gt This is sameas AND gate , So the given circuit acts as AND gas.