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

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

• A. Or
• B. And
• C. Not
• D. Nand

Answer: (B)

The underlying idea is that the output goes high only when both inputs are high. That exact behavior is the AND operation, where Q equals A AND B. Checking the table: 0/0 gives 0, 0/1 gives 0, 1/0 gives 0, and 1/1 gives 1—precisely the truth table for AND. The OR gate would turn on if either input is 1, so it would be 1 for the mixed cases, which doesn’t fit. The NOT gate is a single-input inverter and can’t produce a two-input table like this. The NAND gate is 0 only when both inputs are 1, and 1 otherwise, which also doesn’t match this table. So the gate that fits is the AND gate.

The underlying idea is that the output goes high only when both inputs are high. That exact behavior is the AND operation, where Q equals A AND B. Checking the table: 0/0 gives 0, 0/1 gives 0, 1/0 gives 0, and 1/1 gives 1—precisely the truth table for AND. The OR gate would turn on if either input is 1, so it would be 1 for the mixed cases, which doesn’t fit. The NOT gate is a single-input inverter and can’t produce a two-input table like this. The NAND gate is 0 only when both inputs are 1, and 1 otherwise, which also doesn’t match this table. So the gate that fits is the AND gate.