Free mock exam
Earth Fault Loop Impedance — C&G 2391 Inspection & Testing Practice
Free topic-focused mock exam: 30 random questions from a pool of 54 on Earth Fault Loop Impedance, 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
- 54
Free, no sign-up. Retake as many times as you like — different questions each time.
Sample questions
01What does Zs represent?
- AThe external earth fault loop impedance at the origin
- BThe resistance of the circuit protective conductor only
- CThe insulation resistance between live and earth
- DThe total earth fault loop impedance at the furthest point
Why: Zs represents the total earth fault loop impedance measured at the furthest point of a circuit.
02What does Ze represent?
- AThe total earth fault loop impedance
- BThe external earth fault loop impedance
- CThe phase conductor impedance
- DThe circuit protective conductor resistance
Why: Ze is the external earth fault loop impedance, measured at the origin of the installation.
03What is the relationship between Zs, Ze, and R1+R2?
- AZs = Ze x R1+R2
- BZs = Ze / R1+R2
- CZs = Ze - R1+R2
- DZs = Ze + R1+R2
Why: Zs = Ze + (R1+R2), where R1+R2 is the resistance of the circuit phase and CPC conductors.
Common questions
Is the Earth Fault Loop Impedance 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.
