The output of a thermocouple is: A. a capacitance B. a resistance C. a current D. a voltage E. None of the above

The correct answer is D. A thermocouple is a device that converts heat energy into electrical energy. The output of a thermocouple is a voltage. The voltage is proportional to the temperature difference between the two junctions of the thermocouple.

A capacitance is a measure of the ability of a material to store an electric charge. A resistance is a measure of the opposition to the flow of an electric current. A current is a flow of electric charge.

Option E is incorrect because a thermocouple does produce an output.