Basic Qualification · B-005 Basic electronics and theory · B-005-012-001
Resonance is the condition that exists when:
- A the circuit contains no resistance
- B resistance is equal to the reactance
- C inductive reactance and capacitive reactance are equal
- D inductive reactance is the only opposition in the circuit
Correct answer: C — inductive reactance and capacitive reactance are equal. From the official ISED question bank, verified word for word.
Why
Resonance happens in a circuit when the opposition from inductors, which stores energy in a magnetic field, exactly matches the opposition from capacitors, which stores energy in an electric field. The full explanation — and one for every question — is in Pro.
Practise this section
The theory: Ohm's law, power, series and parallel circuits, AC and DC, frequency and wavelength, decibels, and the metric prefixes the exam leans on.