Inputs A and B are given to the logic circuit shown. Identify the equivalent logic gate represented by the complete circuit.

Options:

• (1) NOR
• (2) NAND
• (3) AND
• (4) OR

The first two gates connected to A and B are NAND gates with both inputs tied together.

A NAND gate with common inputs behaves as a NOT gate.

Therefore:

Output 1 = A'

Output 2 = B'

These outputs enter another NAND gate:

Output = (A' · B')'

Using De Morgan's theorem:

(A' · B')' = A + B

The final NAND gate again acts as an inverter.

Final Output:

(A + B)''

= A + B

Thus the overall circuit performs the OR operation.

Final Answer

Option (4) OR Gate