Free mock exam
RCD Testing — C&G 2391 Inspection & Testing Practice
Free topic-focused mock exam: 30 random questions from a pool of 37 on RCD Testing, drawn from the wider C&G 2391 Inspection & Testing 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
- 37
Free, no sign-up. Retake as many times as you like — different questions each time.
Sample questions
01What does RCD stand for?
- AResidual Circuit Detector
- BResidual Current Device
- CRemote Circuit Disconnector
- DRapid Current Detector
Why: RCD stands for Residual Current Device.
02How does an RCD detect a fault?
- ABy measuring the loop impedance of the earth path
- BBy monitoring the voltage between line and earth
- CBy sensing overcurrent in the line conductor only
- DBy detecting imbalance between live and neutral currents
Why: An RCD detects imbalance between the current flowing in the live and neutral conductors.
03What is the maximum disconnection time for a 30mA RCD at rated residual current?
- A300ms
- B1 second
- C200ms
- D40ms
Why: A general type RCD must disconnect within 300ms at its rated residual current (IΔn).
Common questions
Is the RCD Testing 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.
