JEE Physics · Medium

Semiconductors: Boolean Expression for NAND Gate MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

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Boolean Expression for NAND GateMediumQuestion 20252

Question

A two-input NAND gate can be used as a NOT gate by:
  1. A
    Connecting inputs to different signals
  2. B
    Connecting both inputs together to the same signal
    Correct
  3. C
    Leaving one input at HIGH
  4. D
    Leaving one input at LOW

Correct answer

Connecting both inputs together to the same signal

Explanation

NAND with both inputs tied to A: Y = (A·A)̄ = Ā. This creates a NOT gate using only a NAND gate, demonstrating universality. Similarly, NOR with both inputs tied: Y = (A+A)̄ = Ā.