Free mock exam
AC Theory — Level 3 Electrical Science Practice
Free topic-focused mock exam: 30 random questions from a pool of 35 on AC Theory, 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
- 30
- Time limit
- 35 min
- Pass mark
- 70% · 21/30
- Question bank
- 35
Free, no sign-up. Retake as many times as you like — different questions each time.
Sample questions
01What is the frequency of UK mains supply?
- A60Hz
- B50Hz
- C100Hz
- D25Hz
Why: UK mains electricity operates at 50Hz, meaning 50 complete cycles per second.
02What is the relationship between frequency and period?
- Af = 1/T
- Bf = T
- Cf = 2T
- Df = T²
Why: Frequency (f) is the reciprocal of period (T): f = 1/T. For 50Hz, T = 1/50 = 0.02 seconds = 20ms.
03What is the period of a 50Hz waveform?
- A10ms
- B50ms
- C100ms
- D20ms
Why: Period T = 1/f = 1/50 = 0.02 seconds = 20ms
Common questions
Is the AC Theory 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.
