Red Seal Electrician Practice
Wiring and componentsQuestion 750 of 1506

Why must connections in a thermocouple circuit be clean and tight?

  1. Loose connections increase the thermocouple voltage
  2. The signal is only millivolts, so a small drop gives a big error
  3. The circuit carries several hundred volts at the junction
  4. The connections carry the full motor current and could overheat easily
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Correct answer: The signal is only millivolts, so a small drop gives a big error

Poor joints add resistance and drop part of a very small signal.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 9.5: Thermocouples

Practice wiring and components

Questions last reviewed: 18 October 2026