Basic Qualification · B-005 Basic electronics and theory · B-005-009-009
If you wire two 20-millihenry inductors in parallel, what is the inductance of the combination?
- A 80 millihenries
- B 5 millihenries
- C 10 millihenries
- D 40 millihenries
Correct answer: C — 10 millihenries. From the official ISED question bank, verified word for word.
Why
When two identical inductors, which are coils that store energy in a magnetic field, are wired in parallel, the total inductance drops to exactly half of one component's value. 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.