Free mock exam
Transformers — Level 3 Electrical Science Practice
Free topic-focused mock exam: all 25 questions on Transformers, drawn from the wider Level 3 Electrical Science bank. 35-minute timer, 70% to pass, worked explanation on every question. Use this when you've taken the full mock once and want to drill the topics you got wrong.
- Questions
- 25
- Time limit
- 35 min
- Pass mark
- 70% · 18/25
- Question bank
- 25
Free, no sign-up. Retake as many times as you like — the questions are reshuffled, with the answer order changed.
Sample questions
01What is the basic principle of a transformer?
- AThermal energy transfer
- BElectromagnetic induction
- CChemical energy conversion
- DElectrostatic induction
Why: Transformers work on electromagnetic induction - a changing current in the primary creates a changing magnetic field that induces voltage in the secondary.
02What determines the voltage ratio of a transformer?
- AThe core material
- BThe power rating
- CThe frequency
- DThe turns ratio (N2/N1)
Why: Voltage ratio equals turns ratio: V2/V1 = N2/N1. Double the secondary turns doubles the secondary voltage.
03A transformer has 500 primary turns and 50 secondary turns. If primary voltage is 230V, what is secondary voltage?
- A23V
- B115V
- C2.3V
- D2,300V
Why: V2 = V1 × (N2/N1) = 230 × (50/500) = 230 × 0.1 = 23V. This is a step-down transformer (10:1 ratio).
Common questions
Is the Transformers mock exam free?
Yes — 100% free, no sign-up needed. Questions are pulled at random from a substantial bank, with a worked explanation on every question after you submit.
Can I retake the mock exam?
Yes. Every attempt picks a different random selection and reshuffles the options, so each retake gives you genuinely new questions. No limit on retakes.
Does this count towards the real qualification?
No — this is independent practice material. To gain the actual qualification you need to sit the official assessment through an approved provider.
