Question

In a two input logic gate, when one input is '1' and the other is '0' (zero), the output is '1'. But even if both inputs are '0' (zero), the output is '1'. The logic gate is

• A. an AND gate.
• B. an X-OR gate.
• C. a NAND gate.
• D. a NOR gate.

Hint:

Compare the stated outputs for inputs (1,0) and (0,0) with the truth tables of the listed gates.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept
The gate gives output 1 for inputs (1,0) and also output 1 for inputs (0,0).

Step 2: Check each gate
AND: (1,0) gives 0, so no.
XOR: (0,0) gives 0, so no.
NOR: (1,0) gives 0, so no.
NAND: \(Y=\overline{A\cdot B}\), (1,0) gives 1 and (0,0) gives 1, so yes.

Step 3: Conclusion
Only the NAND gate satisfies both conditions.

Final Answer:
The gate is a NAND gate. \[ \boxed{\text{(C) }\text{a NAND gate.}} \]