Topic: Digital Electronics
The output equivalent circuit of following circuit is (two NAND gates used as NOT gates feeding a third NAND gate)
- A. INVERTER
- B. AND
- C. OR
- D. NOR
Answer: C. OR
Explanation: The first two NAND gates act as inverters, producing $\overline{A}$ and $\overline{B}$. These are fed to a third NAND gate. The final output is $Y = \overline{\overline{A} \cdot \overline{B}}$. By De Morgan's Law, $Y = A + B$, which represents an OR gate.