Red Seal Electrician Practice
Wiring and componentsQuestion 898 of 1506

Why is a real inductor never ideal?

  1. The wire has no resistance, but the core always has some.
  2. Inductors always store zero energy in their magnetic field.
  3. Inductors cannot be made of copper wire in any practical size.
  4. Its wire has resistance and its turns have stray capacitance.
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Correct answer: Its wire has resistance and its turns have stray capacitance.

Real coils behave as inductance with series resistance and some capacitance.

Source: Lessons in Electric Circuits I: DC (Kuphaldt), 15.5: Practical Considerations - Inductors

Practice wiring and components

Questions last reviewed: 18 October 2026