An OR gate has 4 inputs. The number of words (i.e., rows) in the truth table…
2024
An OR gate has 4 inputs. The number of words (i.e., rows) in the truth table will be ________.
Answer: C. 16 — Concept: A truth table lists one row for every distinct combination of a gate's input values, since each binary input can independently be 0 or 1. For a gate…
- A.
4
- B.
8
- C.
16
- D.
More than one of the above
- E.
None of the above
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Correct answer: C
Concept: A truth table lists one row for every distinct combination of a gate's input values, since each binary input can independently be 0 or 1. For a gate with n inputs, the number of independent combinations — and hence rows (words) in the truth table — is 2n, a relationship that holds regardless of which logic function (OR, AND, NAND, etc.) the gate implements.
This OR gate has n = 4 inputs.
Each input independently takes one of 2 possible values (0 or 1).
The number of independent input combinations is therefore 24.
24 evaluates to 16, so the truth table contains 16 rows (words).
Cross-check: A 2-input gate (the familiar AND/OR truth table with rows 00, 01, 10, 11) has 22 = 4 rows; adding two more inputs doubles the count twice — from 4 to 8 to 16 — confirming that a 4-input gate has 16 rows.
The truth table therefore has 16 words (rows), matching the value 16 among the given options.