Which gate produces a logic "0" when both inputs are high?

The gate that produces a logic "0" when both inputs are high is the NOR gate. This type of gate is a combination of an OR gate followed by a NOT gate. In the case of the NOR gate, it only outputs a high signal (logical "1") when both inputs are low. When both inputs are high, as per its defining function, the output is low (logical "0").

For better understanding, let's look at the behavior of the other gates:

• The AND gate produces a "1" only when both inputs are high; otherwise, it produces a "0".

• The OR gate will yield a high output if at least one of the inputs is high. Therefore, it outputs "1" when both inputs are high.

• The XOR (exclusive OR) gate outputs a "1" when exactly one of the inputs is high, giving a "0" only when both inputs are the same, which includes the case of both being high.

Thus, the unique characteristic of the NOR gate is that it specifically returns a logical "0" when both of its inputs are high, making it the correct answer to this question.