Question

A logic gate which gives output 'HIGH' only when its two input terminals are at different logic levels with respect to each other is

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

Hint:

Remember the names literally! "Exclusive-OR" means it functions like an OR gate but strictly excludes the case where both inputs are active together. It acts as an inequality detector or parity checker in digital electronics, producing a high output whenever the inputs disagree.

Answer 1

The Correct Option is D

Step 1: Understanding the Question:
Identify the logic gate that outputs 1 only when its two inputs are different (one 0, one 1).

Step 2: Key Formula or Approach:
Review standard two-input gates: AND outputs 1 only for (1,1). OR outputs 1 for (0,1), (1,0), (1,1). NOR outputs 1 only for (0,0). XOR (Exclusive-OR) outputs 1 exclusively for mismatched inputs (0,1) and (1,0).

Step 3: Detailed Explanation:
Constructing the XOR truth table: for inputs (0,0) → 0; (0,1) → 1; (1,0) → 1; (1,1) → 0. The output goes HIGH precisely when the two input logic levels disagree, perfectly matching the description in the problem.

Step 4: Final Answer:
The described gate is the X-OR gate, option (D).