Which logic gate matches the following truth table: A B -> Q; 0 0 -> 0; 0 1 -> 1; 1 0 -> 1; 1 1 -> 1?

Which logic gate matches the following truth table: A B -> Q; 0 0 -> 0; 0 1 -> 1; 1 0 -> 1; 1 1 -> 1?

• A. And
• B. Nor
• C. Or
• D. Nand

Answer: (C)

The output is high whenever at least one input is high. This behavior is exactly what an OR gate does: it outputs 0 only when both inputs are 0, and outputs 1 in all other cases. In the given table, 0 0 yields 0, while 0 1, 1 0, and 1 1 all yield 1, which matches OR perfectly. Other gates don’t fit: AND would give 0 for 0 1 and 1 0; NOR would give 1 for 0 0; NAND would give 1 for 0 0 and 0 for 1 1. Therefore, this truth table corresponds to the OR gate.

The output is high whenever at least one input is high. This behavior is exactly what an OR gate does: it outputs 0 only when both inputs are 0, and outputs 1 in all other cases. In the given table, 0 0 yields 0, while 0 1, 1 0, and 1 1 all yield 1, which matches OR perfectly. Other gates don’t fit: AND would give 0 for 0 1 and 1 0; NOR would give 1 for 0 0; NAND would give 1 for 0 0 and 0 for 1 1. Therefore, this truth table corresponds to the OR gate.