Question

The output of an OR gate is connected to both the inputs of a NAND gate. The combination will serve as:

• A. AND gate
• B. NOT gate
• C. NAND gate
• D. NOR gate

Answer 1

The correct option is D NOR gate

Let inputs be $A$ and $B$.

Then, output of OR gate is $Y=A+B$

The above output is fed to both the inputs of NAND gate. Hence, output of NAND gate is:

$Z=\overline{Y\cdot Y}=\overline{(A+B)\cdot (A+B)}=\overline{A+B}$

Hence, combination serves as NAND gate.