Free mock exam
Polarity & Functional Testing — C&G 2391 Inspection & Testing Practice
Free topic-focused mock exam: all 25 questions on Polarity & Functional 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
- 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 polarity testing?
- AVerifying correct connection of phase, neutral and earth conductors
- BVerifying the continuity of the ring final circuit
- CVerifying the earth fault loop impedance at each point
- DVerifying the insulation resistance between live conductors
Why: Polarity testing verifies that phase, neutral and earth conductors are correctly connected.
02Why is correct polarity important for single-pole switches?
- ATo ensure the switch breaks both phase and neutral
- BTo ensure the switch breaks the neutral conductor
- CTo ensure the switch breaks the phase conductor
- DTo ensure the switch breaks the earth conductor
Why: Single-pole switches must be in the phase conductor to isolate the load when switched off.
03What could happen if polarity is reversed at a socket outlet?
- AThe circuit will draw twice its normal current
- BThe earth conductor will carry the full load current
- CRisk of shock when maintaining equipment that appears off
- DThe RCD will trip every time the socket is used
Why: Reversed polarity means the neutral is switched, leaving equipment live even when switched off.
Common questions
Is the Polarity & Functional 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.
