You are given two circuits as shown in Figure, which consists of NAND gates. Identify the logic operation carried out by the two circuits.

Solution:

(a) The Boolean expression for NAND gate is given as

Let the output of the NAND gate be .

Therefore, Final output of the combination will be

The given circuit acts as an AND gate.

(b) Boolean expression for NOT gate is

For the first NOT gate, the output is

For the second NOT gate, the output is

The output of the combination will be

This is the Boolean expression for OR gate.