Free mock exam
Safe Isolation — C&G 2391 Inspection & Testing Practice
Free topic-focused mock exam: 30 random questions from a pool of 35 on Safe Isolation, 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
- 35
Free, no sign-up. Retake as many times as you like — different questions each time.
Sample questions
01What is the first step in safe isolation procedure?
- ALock off the supply
- BTest that equipment is dead
- CPost warning notices
- DIdentify the source of supply
Why: The first step is to identify all sources of supply to the circuit or equipment being worked on.
02What device should be used to verify isolation?
- AApproved voltage indicator (AVI)
- BA neon screwdriver tester
- CA non-contact voltage detector pen
- DA standard digital multimeter on the AC range
Why: An approved voltage indicator (AVI) complying with GS38 should be used to verify isolation.
03What is the proving unit used for?
- ATo prove the voltage indicator is working correctly
- BTo measure the loop impedance at the point of isolation
- CTo indicate the phase rotation of a three-phase supply
- DTo discharge any stored energy in the circuit before work
Why: A proving unit is used to prove that the voltage indicator is working correctly before and after testing.
Common questions
Is the Safe Isolation 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.
