Red Seal Electrician Practice
Wiring and componentsQuestion 661 of 1506

Two wires in an industrial control panel carry the same number tag. What does the tag tell the electrician?

  1. The two wires have the same colour and size.
  2. The two wires are electrically common to each other.
  3. The two wires are on separate circuits.
  4. The two wires carry different voltages.
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Correct answer: The two wires are electrically common to each other.

Wires that are electrically common are given the same label, even if their colour or size differs.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 5.8: Building Simple Resistor Circuits

Practice wiring and components

Questions last reviewed: 18 October 2026