The XOR gate gives ______ as output when both inputs are different and ______…
2018
The XOR gate gives ______ as output when both inputs are different and ______ when both inputs are same.
- A.
0, 0
- B.
0, 1
- C.
1, 0
- D.
1, 1
Attempted by 298 students.
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Correct answer: C
An XOR (Exclusive-OR) gate is defined as a difference detector: its output is HIGH (logic 1) exactly when its two inputs disagree, and LOW (logic 0) exactly when its two inputs agree. This is captured by the Boolean identity Y = A ⊕ B, which equals 1 only for the mismatched input pairs (0,1) and (1,0), and equals 0 for the matched pairs (0,0) and (1,1).
Apply this rule to the two conditions asked about in the question:
When the two inputs are different (one is 0 and the other is 1): by the XOR identity, exactly one input is 1, so the output Y = 1.
When the two inputs are the same (both 0 or both 1): by the XOR identity, the inputs cancel each other out, so the output Y = 0.
Cross-check against the full truth table of the gate:
A | B | Y = A ⊕ B |
|---|---|---|
0 | 0 | 0 |
0 | 1 | 1 |
1 | 0 | 1 |
1 | 1 | 0 |
Every row where A and B differ (0,1 and 1,0) gives Y = 1, and every row where A and B match (0,0 and 1,1) gives Y = 0 — confirming the sequence 1, 0 for ‘different, then same’, which is the pairing given in this option.