Red Seal Electrician Practice
Wiring and componentsQuestion 824 of 1506

Why are fuses rated for voltage as well as for current?

  1. Voltage decides how quickly the element heats at the rated current of the fuse
  2. Once it melts, full supply voltage sits across the gap
  3. A higher voltage rating makes the fuse blow at a lower current value
  4. Voltage rating sets the colour code and the size of the fuse body
Show answer

Correct answer: Once it melts, full supply voltage sits across the gap

The fuse must be long enough to stop an arc across the gap at the circuit voltage.

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

Practice wiring and components

Questions last reviewed: 18 October 2026