C & G 2382-18, 2018;  revision paper A

1. BS 7671 applies to

   a). equipment on board ships

   b). lightning protection of buildings

   c). lift installations covered by BS5655

   d). electric vehicle charging.


2.  BS 7671 provides requirements for safety against the risk of

   a).  electric shock on an aircraft

   b).  shock currents on board ships

   c).   fire on offshore installations

   d).   arc fault detection in electrical installations


3.  Which one of the following is not a statutory regulation?

   a).   Electricity at Work Regulations 1989 as amended

   b).   The Supply of Machinery (Safety) Regulations 1992 as amended

   c).   Electrical Safety First Guidance Notes.

   d).   Provision of Work Equipment Regulations


4. BS 7671 identifies that the type of wiring system shall be determined after consideration of

   a).   Electromagnetic interference

   b).   the admissible voltage drop

   c).   harmonics

   d).   the earthing system.


5.  Co-ordination of the operating characteristics of two or more protective devices, such that, on the incidence of an overcurrent or residual current within stated limits, the device intended to operate does so, while the other(s) does (do) not, is known as

   a).   discrimination

   b).   selectivity

   c).   back-up protection

   d).   combined short-circuit protection.



6.  Implementation of measures to assess an electrical installation by means of which its effectiveness is proved, including ascertaining values by appropriate measurement is known as;

   a).   testing

   b).   verification

   c).   inspection

   d).   reporting.


7.  Connection of the EV to the AC supply network utilizing an off-board charger where the control pilot function extends to equipment permanently connected to the AC supply is defined as

   a).   central power supply system

   b).   highway power supply

   c).   Mode 4 charging

   d).   Marina supply point



8.  Which one of the following is a characteristic that should be assessed when considering the compatibility of equipment to avoid harmful effects upon other electrical equipment?

   a).   Ingress protection

   b).   The rating of the protective device at the origin

   c).   Harmonic currents

   d).  The design current



9.  Which one of the following does not comply when considering the connection of final circuits?

   a).   Each final circuit should be connected to a separate way in a distribution board

   b).   The wiring of each final circuit shall be electrically separate from every other final circuit

   c).   Where there are insufficient ways, circuits may be bunched to provide protection

   d).   Due account should be taken of the consequence of the operation of a protective device.


10.  Which protective measures are not generally permitted in each part of an installation?

   a).   Electrical separation for the supply of more than one item of current-using equipment

   b).   automatic disconnection of supply

   c).   extra-low voltage (SELV and PELV)

   d).   double or reinforced insulation.



11.  The maximum disconnection time for a TN-C-S, AC circuit supplying a three-phase sub-distribution board from a 63A fused-switch is

   a).    0.4 seconds

   b).    1 second

   c).     5 seconds

   d).    0.2 seconds


12. BS 7671 requires an RCD with a rated operating current not exceeding 30mA to be provided for

   a).   Socket outlets with a rated current not exceeding 20A

   b).   All 13A socket outlets in all types of installation

   c).   Mobile equipment with a rated current exceeding 32A for use outdoors

   d).   AC final circuits supplying luminaires in domestic properties



13. Where an RCD is used for fault protection the circuit shall also incorporate

   a).   Supplementary bonding

   b).   Earth-free local equipotential bonding

   c).   A residual current monitoring device

   d).   An overcurrent protective device


14. The maximum disconnection time for a TN-S, AC circuit supplying a 63A three-phase socket outlet is

   a).   0.2 second

   b).   0.4 second

   c).   0.5 second

   d).   5 seconds.


15. The maximum Zs value for TN-S, 400V AC circuit supplying a sub-distribution board, protected by a 63A BS88-2 fuse is

   a).   0.78Ω

   b).   0.68Ω

   c).   0.44Ω

   d).   0.36Ω

16.  A 32 A type C circuit-breaker is used to give a disconnection time of 5 seconds in a reduced low voltage system with a nominal voltage to Earth (Uo) of 63.5 V. What is the maximum value of earth fault loop impedance (Zs)?

   a).   0.33Ω

   b).   0.19Ω

   c).   0.16Ω

   d).   0.17Ω


17. The maximum Zs value for TN-S, 400V AC circuit supplying a sub-distribution board, protected by a 63A Type D BS60898

      circuit-breaker is

   a).   0.69Ω

   b).   0.17Ω

   c).   0.35Ω

   d).   0.44Ω



18.  Where electrical equipment in a single location contains flammable liquid, the generally accepted lower limit for a significant quantity is

   a).   10 litres

   b).   20 litres

   c).   25 litres

   d).   50 litres



19.  In conditions BD2, BD3 or BD4, switchgear or control gear placed in an escape route shall be

   a).   Only permitted if they are installed to facilitate evacuation, such as fire alarm call points.

   b).   Accessible to all persons to enable maximum utilization

   c).   Protected by a an RCD as detailed in 415.1

   d).   Enclosed in a non-combustible cabinet or enclosure



20.  In locations of commercial significance, consideration should be given to the use of

   a).   Mineral insulated cable according to BS EN 60702

   b).   Thermoplastic insulated cables capable of withstanding 70˚C

   c).   Category I equipment throughout the installation

   d).   Earth-free local equipotential bonding



21.  To protect against burns, a non-metallic part intended to be touched but not hand-held should attain a maximum

       temperature of no more than

   a).   65˚C

   b).   70˚C

   c).   80˚C

   d).   90˚C


22.  The operating characteristics of a device protecting a conductor against overload shall satisfy which of the following conditions

   a).   The design current (Ib) shall be more than the rated current of the device (In)

   b).   The rated current of the protective device (In) is not less than the design current (Ib)

   c).   The current carrying capacity of the conductor (Iz) does not exceed the rated current of the device (In)

   d).   The current carrying capacity of the conductor (Iz) does not exceed 1.45 x I2



23.  When calculating the effects of fault current, a copper conductor insulated in 90˚C thermosetting material, has a k factor of

   a).   115

   b).   103

   c).   143

   d).   141


24.  Which one of the following is not a consequence of overvoltage requiring protection against transient overvoltages to be provided,

   a).   Interruption of public services and/or damage to cultural heritage

   b).   Interruption of commercial or industrial activity

   c).   Explosion or radioactive emissions

   d).   Serious injury to, or loss of, human life.


25.  The lightning ground flash density value (Ng) relevant to London is

   a).   0.3 Ng

   b).   0.8 Ng

   c).   1.0 Ng

   d).   1.2 Ng



26. Which of the following is not a recognized source of electromagnetic disturbances?

   a).   Electric motors

   b).   Fluorescent lighting

   c).   Electrode water boilers

   d).   Transformers



27.  A main switch intended for operation by ordinary persons, e.g. of a household, shall

   a).   Be capable of being locked in the ‘on’ position to avoid interruption to the supply

   b).   Be capable of breaking the full load current

   c).   interrupt both live conductors of a single-phase supply

   d).   Provide separation of the line conductor of at least 5mm for isolation purposes



28.  A three-phase power cable carrying a current of 15 Amps should be separated from a signal cable by a minimum distance of

   a).   0.25 m

   b).   0.35 m

   c).   0.45 m

   d).   0.58 m


29. A protective conductor shall be identified by a bi-colour combination green-yellow, of which proportion

   a).   70% yellow, 30% green

   b).   80% green, 20% yellow

   c).   75% / 25% either way

   d).   75% green, 25% yellow.



30. A notice shall be fixed prominently near an RCD, indicating that the RCD needs to be tested by operation of the test button every,

   a).   month

   b).   three months/quarterly

   c).   six months

   d).   annually



 Answer paper A

 1   D    110.1.1 – Scope  a general list of inclusions

 2   D    110.2       a list of excluded locations

 3   C    App.2

 4   A    132.7 (vi)

 5   B     Definitions Alphabetical list

 6   A     Definitions Alphabetical list

 7   C     Definitions Alphabetical list

 8   C     331.1 (vi)

 9   C     314.2 – 314.4  Division of installations

10  A     410.3.3 Protection

11  C    411.3.2.3 Disconnection times

12  D    411.3.4

13  D    411.4.5 Fault protection

14  A    Table 41.1

15  A    Table 41.4

16  B     Table 41.6 Reduced low voltage systems

17  C     Table 41.3

18  C    421.1.5

19  D    422.2.2

20  A    422.6

21  C    Table 42.1

22  B    433.1.1

23  C    Table 43.1

24  C    443.4   Also note 7 of 443.1.1

25  B    Fig. 44.2

26  C    444.4.1

27  C    462.1.201

28  D    Table A444.2

29  A    514.4.2

30  C    514.12.2