Red Seal Electrician Practice
Wiring and componentsQuestion 823 of 1506

Which of these can trip a larger circuit breaker?

  1. The magnetic field of the current, or an external protective relay device
  2. Only a bimetallic strip heated by the room temperature in the panel
  3. Only a small fuse that is placed inside the breaker case
  4. A temperature sensor on the supply cable of the building
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Correct answer: The magnetic field of the current, or an external protective relay device

Large breakers are tripped magnetically, or by outside devices that watch the circuit current, called protective relays.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 12.4: Fuses

Practice wiring and components

Questions last reviewed: 18 October 2026