Basic Qualification · B-005 Basic electronics and theory · B-005-010-005
What term equals the ratio of AC voltage to AC current in a system or circuit?
- A Impedance
- B Resistance
- C Reactance
- D Conductance
Correct answer: A — Impedance. From the official ISED question bank, verified word for word.
Why
Impedance is the total opposition a circuit offers to alternating current, calculated simply as the ratio of AC voltage to AC current. 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.