18th Edition Exam Simulator


You have 120 minutes (2 hours) to answer 60 18th Edition Questions. You must score at least 36 to pass. You may check answers after each question or wait until the end of the test to view your results. Click the start button to begin. Best of luck!

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18th Edition Mock Test Questions (Printer-Friendly)

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1. BS7671 applies to the design, erection and verification of which of the following? Mark one answer
A Caravans, parks, and similar sites
B Equipment on board ships covered by BS 8450
C Mines and quarries
D Railway and traction equipment
Correct Answer: A Caravans, parks, and similar sites
Explanation:
2. With regard to additions and alterations to installations, which of the following needs to be considered? Mark one answer
A Installation methods
B Length of cable runs
C Rating and condition of existing equipment
D Timescales and access to site
Correct Answer: C Rating and condition of existing equipment
Explanation:
3. Ideally a characteristic of supply that should be allowed for before an installation design can begin is Mark one answer
A Amount of socket outlets to be installed
B Nature of current AC or DC
C Proximity of persons to supply intake
D The nature of installation of the distribution cabling
Correct Answer: B Nature of current AC or DC
Explanation:
4. It is recommended that every installation is subject to Periodic Inspection in accordance with Chapter Mark one answer
A 25
B 35
C 55
D 65
Correct Answer: D 65
Explanation:
5. Which of the following would describe someone with enough technical knowledge or practical experience appropriate to the work undertaken and to be capable of avoiding electrical danger, risk or hazards? Mark one answer
A A competent person
B A skilled person(electrically)
C A technical person
D An instructed person
Correct Answer: B A skilled person(electrically)
Explanation:
6. A current passing through the body of a person or livestock such as to cause electric shock and likely to cause dangerous effects would be? Mark one answer
A Earth fault current
B Earth leakage current
C Shock current
D Short circuit current
Correct Answer: C Shock current
Explanation:
7. Which earthing arrangement has only one point directly earthed at the source? Mark one answer
A IT system
B PME system
C TNS system
D TT system
Correct Answer: D TT system
Explanation:
8. Which of the following characteristics will be considered in relation to continuity of service? Mark one answer
A Maximum current demand
B Selection of the protective device in order to achieve selectivity
C Size and future proofing of containment system
D Type of wiring system
Correct Answer: B Selection of the protective device in order to achieve selectivity
Explanation:
9. Every installation shall be divided into circuits as necessary, in order to Mark one answer
A Meet the needs of clients with disabilities
B Mitigate the effects of earth faults
C Prevent the de-energization of a circuit intended to be isolated
D Reduce the possibility of unwanted RCD tripping due to excessive protective conductor currents not due to a fault
Correct Answer: D Reduce the possibility of unwanted RCD tripping due to excessive protective conductor currents not due to a fault
Explanation:
10. With regard to electromagnetic compatibility, what shall meet the appropriate EMC compatibility requirements? Mark one answer
A All electrical equipment
B Data cable installation
C Life support equipment
D Sockets and switches
Correct Answer: A All electrical equipment
Explanation:
11. Which of the following comprises of having a protective conductor that is the metallic covering of the cable supplying the installation or a separate conductor? Mark one answer
A I.T system
B PME system
C TN-S system
D TT system
Correct Answer: C TN-S system
Explanation:
12. The following is not recognised as a source of supply for safety services Mark one answer
A Generator sets independent of the normal supply
B Generators
C Primary cells
D Storage batteries
Correct Answer: B Generators
Explanation:
13. Chapter 41 specifies essential requirements regarding protection against electric shock. What else does it deal with? Mark one answer
A Conductors in parallel
B Selection and erection of wiring systems
C The application and coordination of installation protection with regard to external influences
D Tripping times for protective devices
Correct Answer: C The application and coordination of installation protection with regard to external influences
Explanation:
14. To provide additional protection for automatic disconnection of supplies, RCDs may be used provided their residual current values are rated at no more than Mark one answer
A 100 milli amperes
B 30 milli amperes
C 32A
D 50 MA
Correct Answer: B 30 milli amperes
Explanation:
15. In each installation main protective bonding conductors shall be provided to which of the following? Mark one answer
A Exposed metallic building structures
B Local metallic pipework in bathrooms
C Metal pipes that enter a building that have an insulated section at the point of entry
D Radiators
Correct Answer: A Exposed metallic building structures
Explanation:
16. The following would be classed as a potential source of electromagnetic disturbance within an installation. Mark one answer
A Capacitors
B Incandescent lighting
C Inverters
D Power distribution busbars
Correct Answer: D Power distribution busbars
Explanation:
17. To meet 5 second disconnection what is the maximum permissible value of Zs for a 30A BS 3036 fuse? Mark one answer
A 1.04 ohms
B 1.51 ohms
C 2.51 ohms
D D 1667 ohms
Correct Answer: C 2.51 ohms
Explanation:
18. As a protective measure, the use of obstacles and placing out of reach shall only be used in installations restricted to Mark one answer
A Basket ball stadiums
B Competent persons
C Instructed persons
D Skilled persons
Correct Answer: D Skilled persons
Explanation:
19. In order to meet basic protection requirements, horizontal top surfaces of enclosures that are accessible shall be protected to Mark one answer
A IP2X
B IP4X
C IP65
D IPXXXD
Correct Answer: B IP4X
Explanation:
20. What must be carried out when RCDs are not installed protecting socket outlet circuits in installations other than dwellings? Mark one answer
A A maximum current demand assessment
B An as fitted drawing detailing those sockets not protected
C Creation of a documented risk assessment explaining and justifying why RCD is not installed
D Retention of a disclaimer from the client or designer
Correct Answer: C Creation of a documented risk assessment explaining and justifying why RCD is not installed
Explanation:
21. What should be carried out in determining if protection against atmospheric transient voltages is necessary? Mark one answer
A A CRL risk assessment
B A calculation to determine maximum fault currents generated
C An installation survey
D Research into weather patterns
Correct Answer: A A CRL risk assessment
Explanation:
22. When it comes to isolation and switching, in general the PEN conductor shall not be isolated or switched in Mark one answer
A I.T and TT systems
B I.T systems
C TNC and TNCS systems
D TNC and TT systems
Correct Answer: C TNC and TNCS systems
Explanation:
23. Emergency switching shall be provided where a risk of electric shock is involved and shall Mark one answer
A Be readily accessible to all persons
B Disconnect all live conductors
C Disconnect earthing conductors
D Have to be reset by manual operation
Correct Answer: B Disconnect all live conductors
Explanation:
24. In busbar installations, where the equipment is rated at 200A per phase or more, the earthing busbar must have a CSA of at least, Mark one answer
A 100 mm²
B 25 mm²
C 35 mm²
D 50 mm²
Correct Answer: D 50 mm²
Explanation:
25. One of the main recommended methods of reducing EMI in installations is to use Mark one answer
A A bypass conductor for screen reinforcement
B Bridge rectifiers
C Oversized line and neutral conductors
D Suitable containment systems
Correct Answer: A A bypass conductor for screen reinforcement
Explanation:
26. The use of AFDD (ARC fault detection devices) to BS EN 62606 are recommended to provide additional protection against fire in AC circuits, where could devices be used? Mark one answer
A Electric fences covered by BS EN 60335-2-76
B In radio interference suppression equipment
C Locations with combustible construction materials
D On board ships
Correct Answer: C Locations with combustible construction materials
Explanation:
27. What is the maximum disconnection time for a 230 volt AC TT system? a- 0.4 seconds Mark one answer
A 0.07 seconds
B 0.2 seconds
C 0.4 seconds
D 30 milli seconds
Correct Answer: B 0.2 seconds
Explanation:
28. With regard to electrical connections, every connection shall be accessible for inspection and testing purposes except in the case of the following example Mark one answer
A A compound filled or encapsulated joint
B A connection made in roof spaces or ceilings
C A connection made under floors
D A joint designed to be installed in lightning protection systems
Correct Answer: A A compound filled or encapsulated joint
Explanation:
29. Where a PEN conductor is installed it should be identified by the use of the following coloured marks Mark one answer
A Blue throughout it's length with green and yellow at the terminations
B Cream throughout it's length
C Green and yellow throughout it's length
D Green throughout it's length
Correct Answer: A Blue throughout it's length with green and yellow at the terminations
Explanation:
30. Omission of identification by colour or marking on conductors is permitted where Mark one answer
A Numbers are used as an alternative
B SWA is used as a protective conductor
C Three core cables are used in switching arrangements
D Two wire DC power circuits are used
Correct Answer: B SWA is used as a protective conductor
Explanation:
31. What is the derating factor for a cable installed within 200 mm of thermal insulation? Mark one answer
A 0.51
B 0.63
C 0.78
D 0.88
Correct Answer: B 0.63
Explanation:
32. With regard to selection of electrical connections, which of the following is appropriate? Mark one answer
A Accessibility to connections
B Ambient temperature
C The cross sectional area of the conductor
D The voltage to be used
Correct Answer: C The cross sectional area of the conductor
Explanation:
33. When a generator set is used as a safety source, it must comply with Mark one answer
A BS 1362-07
B BS 3036
C BS7698-12
D Local building control recommendations
Correct Answer: C BS7698-12
Explanation:
34. Two or more circuits are allowed in the same conduit, ducting or trunking system provided the requirements of? Mark one answer
A Section 528 are met
B The appropriate calculations have been carried out
C The containment is fixed and supported adequately
D They are of the same type of insulation
Correct Answer: A Section 528 are met
Explanation:
35. Which of the following would meet the requirements for wiring systems to be supported so that they will not collapse in the event of a fire? Mark one answer
A Conduit systems
B Steel or copper clips
C Tie wraps
D Trunking systems
Correct Answer: B Steel or copper clips
Explanation:
36. With regard to corrosive or polluting substances, one method of mitigating the effects in an installation would be to Mark one answer
A Avoid clipping cables direct
B Install warning signs and notices
C Use protective tapes, paints or grease
D Use viscose insulated wiring systems
Correct Answer: C Use protective tapes, paints or grease
Explanation:
37. Emergency lighting systems shall comply with Mark one answer
A BS EN 1838
B BS EN 5839
C Client design criteria
D Local building control specifications
Correct Answer: A BS EN 1838
Explanation:
38. An installation consists of groups of luminaires wired between the line conductors on a polyphase system with a common neutral. What needs to form a part of that installation? Mark one answer
A A linked disconnector for all line conductors
B A risk assessment to be carried out and archived
C Double insulated wiring systems
D Steel containment systems
Correct Answer: A A linked disconnector for all line conductors
Explanation:
39. In relation to wiring systems of luminaires and lighting installations, which of the following is not an appropriate fixed wiring connection method? Mark one answer
A A batten lampholder to BS EN 60598
B A ceiling rose to BS 67
C A connector to BS EN 60998
D An installation coupler to BS EN 61535
Correct Answer: C A connector to BS EN 60998
Explanation:
40. Earthing conductors that are made of steel are to be buried and are protected against mechanical damage and are corrosion can be of a minimum c.s.a. of Mark one answer
A 10 mm²
B 16 mm²
C 2.5 mm²
D 4 mm²
Correct Answer: A 10 mm²
Explanation:
41. Every firefighter's switch shall Mark one answer
A Be easily visible, accessible and labelled accordingly
B Be no more than 1.75m off the floor level
C Comply with BS EN 1362
D Comply with Part M building regulations
Correct Answer: A Be easily visible, accessible and labelled accordingly
Explanation:
42. Whilst carrying out inspection as part of initial verification of an installation, which of the following should not be checked? Mark one answer
A Erection methods
B Identification of conductors
C Presence of diagrams, instructions and similar information
D Selection and installation of suitable STDs where required
Correct Answer: D Selection and installation of suitable STDs where required
Explanation:
43. Where an installation does not include a new circuit or a replacement consumer unit/ distribution board has not been installed, what type of certificate should be issued to the client or person ordering the work? Mark one answer
A Condition Report
B Electrical Installation Short Form Certificate
C Minor Works Certificate
D Periodic Inspection Certificate
Correct Answer: C Minor Works Certificate
Explanation:
44. What should be carried out before a measurement of earth fault loop impedance is taken? Mark one answer
A A discussion with the client on suitable alternatives
B A high current test of any extraneous metalwork
C An electrical continuity test
D Safe isolation of supplies
Correct Answer: C An electrical continuity test
Explanation:
45. What is the minimum value acceptable of insulation resistance on a SELV system? Mark one answer
A 0.5 MegOhms
B 2 MegOhms
C >299MegOhms
D >300 MegOhms
Correct Answer: A 0.5 MegOhms
Explanation:
46. On construction sites, selection and erection of equipment shall meet the standards layed down in Mark one answer
A BS 7672
B BS EN 61439-4
C BS EN 721786
D The on site guide
Correct Answer: B BS EN 61439-4
Explanation:
47. To avoid ingress of water and when involved in installation of electrical charging installations, all equipment shall be to a minimum of Mark one answer
A IP 68
B IP65
C IPX4
D IPXX2
Correct Answer: C IPX4
Explanation:
48. In embedded heating systems, what is the minimum distance that heating elements should be installed in air from ignitable structures in order to meet Chapter 42 requirements? Mark one answer
A 100 mm
B 10mm
C 125 mm
D 50mm
Correct Answer: B 10mm
Explanation:
49. Which of the following types of cables could be installed to compensate for movement on a floating landing stage of an inland navigation vessel? Mark one answer
A Armoured cable with thermoplastic or elastomeric covering
B MIMS
C Multicore cabling to BS 45890
D SY cable with butyl rubber sheathing
Correct Answer: A Armoured cable with thermoplastic or elastomeric covering
Explanation:
50. What is the maximum rated residual current value for an RCD used to protect a cable that supplies the power to a temporary structure on an exhibition, show or stand? Mark one answer
A 100 mA
B 30 mA
C 300 mA
D 32 A
Correct Answer: C 300 mA
Explanation:
51. For showers without a basin, what is the height of zone 0? Mark one answer
A 0.1 m
B 1 m
C 10 mm
D 50 mm
Correct Answer: A 0.1 m
Explanation:
52. Submerged luminaires installed in swimming pools should meet the requirements of Mark one answer
A AD3
B BS EN 60598
C BS EN 60898
D IP44
Correct Answer: B BS EN 60598
Explanation:
53. What is particular about a FELV system in a medical location? Mark one answer
A Associated enclosures should be non conductive
B It should be fused on the supply side
C It should be tested in accordance with Chapter 6
D It should not be relied upon for protection against shock
Correct Answer: D It should not be relied upon for protection against shock
Explanation:
54. On a construction site, which of the following is true with regard to wiring systems used? Mark one answer
A Cables installed over roadways should be installed to a minimum height of 8 meters
B Cables installed should be steel wire armoured
C Cables should be installed within a duct or containment system
D Cables should not be installed across a road unless adequate mechanical protection is provided
Correct Answer: D Cables should not be installed across a road unless adequate mechanical protection is provided
Explanation:
55. Socket outlets installed in agricultural environments should Mark one answer
A Be protected by a 300 mA RCD
B Be rated to IP 68
C Comply with BS EN 60309-1
D Incorporate a double pole switch
Correct Answer: C Comply with BS EN 60309-1
Explanation:
56. Good design should consider energy efficiency within an installation. Which of the following should be taken into account? Mark one answer
A Costs incurred by the installation team
B Power factor efficiency
C Reduction of energy losses within the installation
D Type of insulation used on cabling
Correct Answer: C Reduction of energy losses within the installation
Explanation:
57. The maximum floor area served by a 20A radial power circuit wired with a 2.5mm conductor should be no more than Mark one answer
A 100 m²
B 25 m²
C 50 m²
D It is unlimited
Correct Answer: C 50 m²
Explanation:
58. What value of current would it typically require to disconnect a 6A Type B circuit breaker to BS60898 in 0.1 of a second? Mark one answer
A 12A
B 30A
C 6A
D 8A
Correct Answer: B 30A
Explanation:
59. The current carrying capacity for a 2.5 mm², 70 degree C rated thermoplastic sheathed twin and earth flat cable installed within a stud wall to method 103 would be Mark one answer
A 13.5A
B 21A
C 25A
D 27A
Correct Answer: A 13.5A
Explanation:
60. With regard to voltage drop within a consumer's installation, what is the maximum value allowed for a 230 volt lighting circuit on a typical public supply network? Mark one answer
A +/- 10%
B 11.5 volts
C 3 volts
D 6.9 volts
Correct Answer: D 6.9 volts
Explanation: