Basic Qualification · B-005 Basic electronics and theory · B-005-011-004
The primary winding of a transformer has 250 turns, and the secondary has 500 turns. If the input voltage is 120 volts, what is the secondary voltage?
- A480 V
- B620 V
- C60 V
- D240 V
Correct answer: D — 240 V. From the official ISED question bank, verified word for word.
Why
The secondary voltage is 240 volts because the transformer doubles the input voltage when the secondary coil has twice as many wire turns as the primary coil. 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