Thermocouples are temperature-sensing devices that produce what type of signal when the temperature increases?

• A. Milliamp level current
• B. Millivolt level voltage
• C. Volts
• D. Kilovolt

Answer: (B)

Thermocouples generate a small electrical voltage when there is a temperature difference between their junctions, due to the Seebeck effect. That output is a voltage, and its magnitude is typically in the millivolt range, not a large voltage. They don’t inherently provide current (milliamps) or kilovolts; the signal is a tiny millivolt-level voltage that often needs amplification and proper cold-junction compensation for accurate measurement.