Question

(i) Identify the logic gates marked P and Q in the given logic circuit. 

(ii) Write down the output at X for the inputs A = 0, B = 0 and A = 1, B = 1.

Answer 1

(i) Gate P is a NAND gate, and gate Q is an OR gate. 

(ii) Boolean expression for the above logic circuit is

X = 1 [using boolean identities] 

Thus output at X is going to be 1 for all the possible inputs at A and B.