Which logic gate produces a low output if any input is high?

The NAND gate produces a low output if any input is high because it is designed to output the opposite of the AND gate. In the case of an AND gate, the output is high only when all inputs are high. Therefore, if any input is high, the AND gate delivers a high output only if every single input meets this condition.

In contrast, the NAND gate will output a low signal only when all inputs are high. If even one input is low, the NAND gate outputs a high signal. Hence, it effectively turns low when any single input is activated. This unique behavior allows the NAND gate to act as a fundamental building block in digital electronics, especially in creating other logic functions through combinations of gates.

The other gates like AND, OR, and XOR produce high output under certain conditions when specific inputs are low or high. Thus, their operation does not align with the criteria specified in the question, where a low output is required for any input being high.