Basic Qualification · B-005 Basic electronics and theory · B-005-011-003
A transformer with a single 12-volt secondary draws 0.5 amperes through its 120-volt primary. Assuming no losses, what current is drawn from the secondary?
- A50 amperes
- B5 amperes
- C2.5 amperes
- D25 amperes
Correct answer: B — 5 amperes. From the official ISED question bank, verified word for word.
Why
With no losses, the power going into the transformer must equal the power coming out. The full explanation — and one for every question — is in Pro.
Practise this section
Basic electronics and theory is section B-005 of the Basic exam: 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.
Drill B-005 — free, no account