Free 18th Edition Practice Questions: Test Yourself Before the Exam

The best way to prepare for the 18th Edition exam isn’t just reading BS 7671 — it’s testing yourself under pressure. Practice questions reveal the gaps between what you think you know and what you can actually recall when it matters.

 

Below you’ll find 15 free practice questions covering the topics that appear most often in the City & Guilds 2382-22 exam. Each question includes the correct answer with a full explanation referencing the specific regulation, so you’re not just learning what’s right — you’re learning why it’s right and where to find it in the book.

 

Work through them honestly before checking the answers. Time yourself if you want a realistic test — at exam pace, you’d have 2 minutes per question.

How to Use These Questions

These questions mirror the format of the real exam: multiple-choice with four options, one correct answer.

 

Approach	Why It Works
Do all 15 before checking answers	Simulates exam conditions — you can’t check as you go in the real thing
Use your copy of BS 7671	It’s an open-book exam, so practise navigating your tabbed book
Note which questions you guess on	A lucky guess doesn’t mean you know the topic — review it anyway
Time yourself	15 questions at exam pace = 30 minutes maximum

 

Exam tip: If you haven’t already set up your book with coloured tabs for key tables and regulations, do that before working through these questions. Our guide on how to pass the 18th Edition exam first time covers exactly what to tab and why.

 

Part 2 — Definitions

Question 1. What is the definition of an “extraneous-conductive-part” according to BS 7671?

 

• A) A conductive part of equipment that can be touched and is not normally live
• B) A conductive part liable to introduce a potential, not forming part of the electrical installation
• C) A conductive part that is connected to the main earthing terminal
• D) A protective conductor connecting exposed-conductive-parts to the main earthing bar

 

Question 2. In a SELV system, which of the following statements is correct?

 

• A) The circuit may be connected to earth
• B) The nominal voltage must not exceed 50V AC
• C) Live parts must not be connected to earth or to live parts of other systems
• D) An RCD must always be provided for fault protection

 

Part 4 — Protection for Safety

Question 3. In a TN system, what is the maximum disconnection time for a 230V final circuit rated at 32A or less?

 

• A) 0.2 seconds
• B) 0.4 seconds
• C) 1 second
• D) 5 seconds

 

Question 4. According to Regulation 415.1.1, additional protection by an RCD with a rated residual operating current not exceeding 30 mA shall be provided for socket-outlets with a rated current not exceeding which value?

 

• A) 16A
• B) 20A
• C) 32A
• D) 63A

 

Question 5. The overload protection coordination requirement Ib ≤ In ≤ Iz means:

 

• A) The cable capacity must exceed the design current, which must exceed the device rating
• B) The design current must not exceed the device rating, which must not exceed the cable current-carrying capacity
• C) The fuse rating must exceed the cable capacity and the design current
• D) The device rating must equal the design current and the cable capacity

 

Question 6. What is the maximum permitted measured earth fault loop impedance (Zs) for a 32A Type B MCB, after applying the 80% rule?

 

• A) 1.37 Ω
• B) 1.20 Ω
• C) 1.10 Ω
• D) 0.96 Ω

 

Part 5 — Selection and Erection

Question 7. According to Regulation 525, the maximum voltage drop for a lighting circuit from the origin of the installation is:

 

• A) 2.5%
• B) 3%
• C) 4%
• D) 5%

 

Question 8. Where the line conductor of a circuit is 25 mm² copper, what is the minimum cross-sectional area of the CPC according to Table 54.7?

 

• A) 10 mm²
• B) 16 mm²
• C) 25 mm²
• D) 12.5 mm²

 

Question 9. The adiabatic equation used to verify that a CPC is adequately sized is:

 

• A) S = (I × t) / k
• B) S = (I² × t) / k
• C) S = √(I² × t) / k
• D) S = I / (k × t)

 

Part 6 — Inspection and Testing

Question 10. During initial verification, which test must be carried out first after the visual inspection?

 

• A) Insulation resistance
• B) Earth fault loop impedance
• C) Continuity of protective conductors
• D) Polarity

 

Question 11. What is the minimum acceptable insulation resistance reading for a circuit tested at 500V DC?

 

• A) 0.5 MΩ
• B) 1.0 MΩ
• C) 2.0 MΩ
• D) 0.25 MΩ

 

Question 12. Which document is issued on completion of a periodic inspection?

 

• A) Electrical Installation Certificate (EIC)
• B) Minor Electrical Installation Works Certificate (MEIWC)
• C) Electrical Installation Condition Report (EICR)
• D) Domestic Electrical Installation Certificate

 

Part 7 — Special Installations

Question 13. In a bathroom, what is the maximum height from floor level that defines Zone 1?

 

• A) 2.0 m
• B) 2.25 m
• C) 2.5 m
• D) 3.0 m

 

Question 14. On a construction site, what is the required supply voltage for portable hand tools?

 

• A) 230V single phase
• B) 110V centre-tapped to earth
• C) 55V single phase
• D) 400V three phase

 

Part 8 — Prosumers

Question 15. What is the purpose of anti-islanding protection in a prosumer’s installation?

 

• A) To prevent the installation from consuming power from the grid
• B) To prevent the local generator from energising the distribution network during a supply outage
• C) To isolate the solar panels during darkness
• D) To prevent overloading of the consumer unit

 

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Answers and Explanations

Now check your answers. For every question you got wrong, find the regulation in your copy of BS 7671 and read the context around it — understanding the surrounding text is just as important as knowing the answer.

 

Definitions (Questions 1–2)

 

Q	Answer	Explanation
1	B	An extraneous-conductive-part is a conductive part liable to introduce a potential, including earth potential, and not forming part of the electrical installation (Part 2 definitions). Option A describes an exposed-conductive-part — confusing these two is one of the most common exam mistakes.
2	C	In a SELV system, live parts must not be connected to earth or to the live parts of other systems (Part 2). PELV may be connected to earth; SELV may not. The voltage limit of 50V AC applies to both SELV and PELV, but the earthing distinction is the key exam point.

 

Protection for Safety (Questions 3–6)

 

Q	Answer	Explanation
3	B	Regulation 411.3.2.2 requires a maximum disconnection time of 0.4 seconds for TN systems on final circuits not exceeding 32A. For TT systems the time is 0.2 seconds (Reg. 411.3.2.4). Distribution circuits in both systems get 5 seconds.
4	C	Regulation 415.1.1 requires additional protection by a 30 mA RCD for socket-outlets with a rated current not exceeding 32A for general use.
5	B	Regulation 433.1 states that the design current (Ib) must not exceed the nominal rating of the protective device (In), which in turn must not exceed the current-carrying capacity of the cable (Iz). This is the fundamental cable sizing and protective device coordination requirement.
6	C	Table 41.3 gives 1.37 Ω for a 32A Type B MCB. When comparing a live measurement against this value, you apply the 80% rule: 1.37 × 0.8 = 1.10 Ω. A measured value above 1.10 Ω fails, even though it’s below the table value. See our full guide on Maximum Zs and the 80% rule for worked examples.

 

Selection and Erection (Questions 7–9)

 

Q	Answer	Explanation
7	B	Regulation 525 limits voltage drop to 3% for lighting and 5% for other circuits from the origin of the installation.
8	B	Table 54.7: for line conductors between 16 mm² and 35 mm², the minimum CPC size is 16 mm². Below 16 mm² the CPC must match the line conductor; above 35 mm² it’s half the line conductor size.
9	C	The adiabatic equation is S = √(I² × t) / k, where S is the minimum conductor cross-sectional area, I is the fault current, t is the disconnection time, and k is a factor from Table 54.4 (115 for copper/PVC).

 

Inspection and Testing (Questions 10–12)

 

Q	Answer	Explanation
10	C	Regulation 612 specifies that continuity of protective conductors is the first test after visual inspection. The sequence matters because each subsequent test depends on the results of the previous one — you must know the CPCs are intact before you can trust any other reading.
11	B	Regulation 612.3 requires a minimum insulation resistance of 1.0 MΩ when tested at 500V DC for circuits rated between 50V and 500V. Values below this indicate a potential insulation breakdown.
12	C	An EICR (Electrical Installation Condition Report) is issued after periodic inspection and testing. An EIC is for new installations, and a MEIWC is for minor additions or alterations to existing installations.

 

Special Installations and Prosumers (Questions 13–15)

 

Q	Answer	Explanation
13	B	Section 701 defines Zone 1 in a bathroom as extending up to 2.25 m from floor level above Zone 0.
14	B	Section 704 requires 110V centre-tapped to earth for portable hand tools on construction sites. This gives 55V to earth, reducing electric shock risk. The question tests whether you know the supply specification, not just the voltage to earth.
15	B	Regulation 802.4 requires anti-islanding protection to prevent the local generator from energising the distribution network during a supply outage. This protects network engineers and the public from unexpected live conductors.

 

How Did You Score?

 

Score	What It Means	Next Step
13–15	Strong — you know the regulations well	Focus on speed and book navigation under timed conditions
10–12	Solid foundation with some gaps	Review the topics where you dropped marks, then take a full 60-question mock
7–9	You understand the basics but need more practice	Work through each Part systematically — start with Parts 4 and 5
Below 7	More study needed before the exam	Read our guide on how long to study for the 18th Edition and build a structured plan

 

Important: 15 questions is a useful check, but the real exam has 60 questions across all 8 Parts plus the Appendices. A short quiz can’t cover everything — use it to identify weak areas, then target those in your revision.

 

Keep Practising

These 15 questions cover the fundamentals, but the City & Guilds 2382-22 exam draws from the full breadth of BS 7671. To build genuine confidence, you need to work through hundreds of questions across every topic and sit full-length mock tests under timed conditions.

 

Test yourself on the topics that carry the most marks:

• Part 4 — Protection for Safety quiz
• Part 5 — Selection and Erection of Equipment quiz
• Part 6 — Inspection and Testing quiz
• Part 7 — Special Installations quiz

 

Our app includes 580+ practice questions covering all 8 Parts of BS 7671 with detailed explanations referencing specific regulation numbers. Every answer tells you not just what’s correct, but why — and exactly where to find it in the book. The app also includes full 60-question mock tests weighted to match the real exam distribution, with a countdown timer so you can practise under realistic pressure.

 

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