Part P Practice Test

Part P Exam at a Glance

What changed for Part P in 2026

• Oct 24, 2026: Delivery (2383-10 Level 3 Award) changed to Open-book online multiple-choice test (previously Open-book online multiple-choice test at an approved centre).^[2]

What the Part P is and how it works

According to City & Guilds of London Institute, “Pass mark: The pass mark for this examination is set at approximately 65%.”^[1]

Exam Format and Delivery

The City & Guilds 2383-10 Level 3 Award in the Building Regulations for Electrical Installations in Dwellings assesses knowledge of statutory building regulations and standards applicable to domestic electrical work. The assessment is delivered as an open-book online multiple-choice test administered through approved assessment centres.

Candidates must answer 35 multiple-choice questions within a time limit of 60 minutes. Because the assessment is open-book, candidates may refer to approved reference publications while answering questions during the allocated time.

Eligibility and Scoring

This qualification is approved for learners aged 18 or above. The test is graded on a pass/fail basis, with the pass mark set at approximately 65%. Candidates who achieve this standard receive the qualification award.

The last registration date for the 2383-10 qualification is 31 Dec 2028. Retake policies, candidate registration arrangements, and testing fees vary by assessment centre and provider, so candidates should check directly with their chosen City & Guilds approved centre for specific local booking and administration procedures.

Worked examples: how to reason through Part P questions

These are practice questions written for this site, not questions from the real exam. Each explanation shows why the right answer is right and why the others are wrong.

Example 1

Question: What minimum cable cross-sectional area (CSA) is typically required for a domestic cooker circuit supplying a 45A cooker control unit?

1. 4.0 mm²
2. 6.0 mm²
3. 10.0 mm²
4. 16.0 mm²

Answer: C. 10.0 mm²

Explanation:

Option C is correct because a 10.0 mm² twin and earth cable is typically required for a 45A cooker circuit once standard installation methods, thermal insulation derating, and voltage drop calculations under BS 7671 are applied. Option A (4.0 mm²) and Option B (6.0 mm²) are incorrect because cables of 4.0 mm² and 6.0 mm² lack sufficient current-carrying capacity for a 45A protective device under typical domestic installation conditions, creating an overheating risk. Option D (16.0 mm²) is incorrect because a 16.0 mm² cable is unnecessarily large for standard domestic cooker loads and difficult to terminate in a 45A control unit. The general rule is to determine cable size by matching the protective device rating against tabulations in BS 7671 while factoring in installation methods and derating.

Example 2

Question: How does splitting circuits between two RCDs in a consumer unit reduce the impact of nuisance tripping?

1. It limits the number of circuits on each RCD so leakage currents don't accumulate as easily, and limits how many circuits are lost when one RCD trips
2. It doubles the tripping sensitivity of each RCD
3. It prevents overloads
4. It increases the rated current of each circuit

Answer: A. It limits the number of circuits on each RCD so leakage currents don't accumulate as easily, and limits how many circuits are lost when one RCD trips

Explanation:

Option A is correct because dividing circuits across two RCDs restricts the accumulation of normal earth leakage current across connected equipment, preventing unwanted trips while ensuring that an earth fault on one device disconnects only the circuits wired to that specific RCD rather than disconnecting the entire installation. Option B is incorrect because dividing circuits across multiple devices does not double the tripping sensitivity of each RCD; the operating threshold remains unchanged. Option C is incorrect because RCD devices protect against earth leakage faults, not overcurrent or overloads, which require circuit breakers or fuses. Option D is incorrect because the rated current of an individual circuit is determined by its protective device and cable size, not the RCD configuration. The general rule is to separate circuits across RCDs to minimize disruption from residual current faults.

Example 3

Question: What must be checked about the existing earthing arrangement before replacing a consumer unit?

1. The type of earthing system (TN-S, TN-C-S, TT), the condition and size of the earthing conductor, and compliance with the current requirements of BS 7671
2. Only the visual condition of the earthing conductor
3. Only the earthing system type
4. Earthing does not need to be checked during consumer unit replacement

Answer: A. The type of earthing system (TN-S, TN-C-S, TT), the condition and size of the earthing conductor, and compliance with the current requirements of BS 7671

Explanation:

Option A is correct because an installer must confirm the earthing system type (TN-S, TN-C-S, TT), assess the physical condition and cross-sectional sizing of the earthing conductor, and verify full compliance with BS 7671 before replacing a consumer unit. Option B is incorrect because a purely visual inspection ignores conductor sizing, continuity, and system characteristics required to verify protective disconnection. Option C is incorrect because identifying the earthing system type alone does not confirm that the conductor is undamaged, adequately sized, or properly connected. Option D is incorrect because regulations mandate that earthing and bonding arrangements must be adequate before altering or replacing a consumer unit. The general rule is that supply earthing arrangements must always be verified and brought into compliance with BS 7671 before energizing replacement distribution equipment.

How to use these practice tests

Preparing for the 2383-10 examination requires familiarizing yourself with approved regulatory documents and learning how to find answers efficiently during an open-book test. Begin by reviewing statutory guidance alongside the Part P Building Regulations Part P and Part P BS 7671 IET Wiring Regulations practice questions.

Work through focused topic sets to address specific technical procedures:

• Practise installation rules with Part P Cable Selection and Wiring Systems and Part P Circuit Design and Protection.
• Review equipment replacement requirements through Part P Consumer Unit Replacement.
• Study special locations and verification steps via Part P Special Installations (Bathrooms/Outdoors) and Part P Inspection & Testing.

Once you are comfortable with individual topics, attempt full practice runs using the FREE Part P PRACTICE TEST. Time yourself to answer 35 multiple-choice questions within 60 minutes, mirroring the official assessment. Aim to consistently achieve the approximately 65% benchmark while checking your permitted reference material.

Sources & last verified

1. City & Guilds of London Institute — number of questions, time limit, passing score, eligibility (official source). “Total 35 100” Verified Oct 24, 2026.
2. City & Guilds of London Institute — delivery, registration deadline (official source). “You'll demonstrate what you've learned through an open-book, multiple-choice online assessment.” Verified Oct 24, 2026.

How we verify: editorial & fact-checking policy. Report an error: contact us.