Free mock exam
Safe Isolation — Level 3 Fault Diagnosis Practice
Free topic-focused mock exam: all 30 questions on Safe Isolation, drawn from the wider Level 3 Fault Diagnosis 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
- 30
Free, no sign-up. Retake as many times as you like — the questions are reshuffled, with the answer order changed.
Sample questions
01According to GS38, what is the maximum length of exposed metal at a test probe tip?
- A20 mm of exposed metal at the tip
- BNo limit, provided finger barriers are fitted
- C10 mm of exposed metal at the tip
- D4 mm of exposed metal at the tip
Why: GS38 recommends no more than 4 mm of exposed metal at the probe tip (many manufacturers limit this to 2 mm), together with finger barriers, to protect against accidental contact and arc flash.
02The correct sequence for safe isolation is:
- ASecure, identify, work, then isolate the supply
- BIdentify, isolate, secure, prove dead, prove tester
- CIsolate, work, then test for dead afterwards
- DProve dead, isolate, then secure the supply
Why: Safe isolation follows: identify circuit, isolate from supply, secure isolation (lock off), prove tester, test for dead, prove tester again.
03Why is it necessary to prove the voltage tester before AND after testing for dead?
- ATo comply with the manufacturer warranty terms
- BTo increase the sensitivity of the tester for low voltages
- CTo recharge the tester battery between readings
- DTo ensure the tester is working correctly and hasn't failed during testing
Why: Proving before confirms the tester works, proving after confirms it still works - if the tester failed during testing, a false 'dead' reading could result.
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.
