When heated, a thermocouple generates which type of electrical signal?

When heated, a thermocouple generates which type of electrical signal?

• A. AC voltage
• B. Pulsed current
• C. DC voltage
• D. Resistance change

Answer: (C)

When two dissimilar metals are joined and there’s a temperature difference, the Seebeck effect creates a small electromotive force. This manifests as a voltage whose polarity depends on which side is hotter. If the temperature difference is steady, the produced voltage is essentially constant, i.e., a direct current (DC) voltage. If the temperature varies, the voltage varies in kind with that change, but it’s still a voltage signal generated by the thermocouple, not an AC waveform or a pulsed current by itself. A thermocouple does not inherently produce a change in resistance as its primary signal.

When two dissimilar metals are joined and there’s a temperature difference, the Seebeck effect creates a small electromotive force. This manifests as a voltage whose polarity depends on which side is hotter. If the temperature difference is steady, the produced voltage is essentially constant, i.e., a direct current (DC) voltage. If the temperature varies, the voltage varies in kind with that change, but it’s still a voltage signal generated by the thermocouple, not an AC waveform or a pulsed current by itself. A thermocouple does not inherently produce a change in resistance as its primary signal.