Question

In digital logic, what is the dual of the OR operation?

• A. NOT
• B. AND
• C. XOR
• D. NAND

Hint:

Duality → OR ↔ AND, 0 ↔ 1.

Answer 1

The Correct Option is B

Concept: In Boolean algebra, the principle of duality states that every algebraic expression remains valid if operators and identity elements are interchanged.
Step 1: Duality principle.
To find the dual:

• Replace OR (+) with AND ($\cdot$)
• Replace AND ($\cdot$) with OR (+)
• Replace 0 with 1 and 1 with 0

Step 2: Apply to OR operation.
The dual of OR is AND.
Step 3: Example.
\[ A + B \quad \leftrightarrow \quad A \cdot B \]
Step 4: Conclusion.
Thus, the dual of the OR operation is AND.