Based on C&G2382 - BS7671:2018 (Amendment 2:2022) Electrical Regulations Mock Exam (30 questions

The choice of the type of wiring system and the method of installation shall consider all except
1. Load current
2. Nature of the location
3. Voltage
4. Short-circuit current
Equipment may not be fixed
1. On covers which can inadvertently be removed
2. On equipment mouldings
3. On or in skirting-board trunking
4. On or in steel cable trunking
When conductors are identified by the number zero, it;
1. Identifies the neutral conductor
2. May not be used
3. Identifies the protective conductor
4. Identifies the line conductor
Potential sources of electromagnetic disturbances include all except for
1. Batteries
2. Rectifiers
3. Electric motors
4. Discharge lighting
Where protection is provided against overload and not fault current the device providing protection may be
1. an Inverse time lag protective device
2. a 30mA RCD
3. a BS 88-2 fuse
4. a RCD with a maximum rating of 300mA
A 1500V DC voltage between conductors is classified as being
1. Band II
2. Band I
3. ELV extra low voltage
4. RLV reduced low voltage
An interrupting device shall be installed in such a way that it can be easily recognised and effectively operated where necessity for immediate interruption of the supply, is termed as
1. Emergency control
2. Environmental condition
3. Accessibility of electrical equipment
4. Protective equipment
For a shower installed without a basin
1. Zone 1 is increased to 1.20m
2. Zone 2 applies
3. Zone 2 is 0.6m from the water-outlet
4. Zone 0 does not apply
For a construction site, reduced low voltage is the preferred protection method for all except
1. Portable hand lamps in confined locations
2. Portable hand lamps
3. Local lighting up to 2kW
4. Portable hand tools
Three phase 4-wire system including a PEN conductor has only
1. Three live conductors
2. Four live conductors
3. Two live conductors
4. Three conductors
Maintainability should be a consideration when assessing
1. The reliability of equipment
2. Installation erection scheduling
3. The cost of repair
4. The time taken for repair
For Electric Vehicle charging, Mode 2 charging socket-outlets should not exceed
1. 32A
2. 13A
3. 20A
4. 16A
During inspection of a part of an installation that requires testing that part shall normally
1. Be disconnected from the supply
2. Have current using equipment operating
3. Be connected to the normal supply
4. Have current using equipment connected
Any intended departure from BS 7671
1. Shall not result in a degree of safety less than that when complying with BS 7671
2. Is not allowed
3. May lessen the resulting degree of safety
4. Does not need to be noted on the electrical test certificate
A supplementary bonding conductor with mechanical protection connecting two extraneous-conductive parts shall have a minimum c.s.a. of mmsq
1. 2.5
2. 4.0
3. 1.5
4. 16
Where screened signal cables are common to several buildings supplied from a TT system, a copper bypass equipotential bonding conductor shall have a minimum c.s.a. of
1. 16 mmsq
2. 10 mmsq
3. 6 mmsq
4. 25 mmsq
The co-ordination between fault current and overload protective devices is that the overload protective device can withstand without damage
1. The energy let through by the fault current protective device
2. The overload current of the circuit
3. The nominal voltage rating of the fault current protective device
4. The design current of the circuit
When a PEI is in island mode, all live conductors shall be
1. Disconnected from the DNO supply
2. Switched independently
3. Connected to the public supply
4. Connected in parallel with the public supply
The Maximum earth fault loop impedance Zs for a BS 3036 fuse rated at 30A and 0.4s disconnection time is
1. 1.04 ohms
2. 2.2 ohms
3. 1.77 ohms
4. 2.68 ohms
Which one of the following is not a characteristic of the supply
1. The nature of fault and harmonic currents
2. Frequency
3. Prospective short-circuit current
4. Earth fault loop impedance external to the consumer's TN installation
BS 7671 states that installations shall have an adequate level of immunity against
1. Electromagnetic disturbances
2. Unexpected circumstances
3. Flooding
4. Earth tremors
RCD for the protection against the risk of fire shall have a rating not exceeding
1. 300mA
2. 30mA
3. 10mA
4. 100mA
For device coordination between upstream fuse and downstream circuit breaker the following condition should apply
1. the minimum pre-arcing I(sq) t value of the fuse should be higher than the maximum let through I(sq) t value of the circuit breaker.
2. the peak let-through current of the fuse should be lower than the instantaneous tripping current of the circuit breaker.
3. the minimum pre-arcing I(sq) t value of the circuit breaker should be higher than that of the fuse.
4. selectivity in case of short circuit is verified by comparison of the I(sq) t values on the inlet side.
For an IT installation supplying offices harmonic currents in a three phase circuit may require
1. An increased c.s.a for the neutral conductor
2. Insulation monitoring devices
3. An RCD rated at 400mA
4. Use of a separate protective device for each circuit
Protection against transient overvoltages shall be provided where the consequence caused by overvoltage could result in all except
1. Affect a small group of co-located individuals
2. Interruption of commercial activity
3. Interruption of public services
4. Serious injury
A single-core 90degC thermosetting cable has an aluminium conductor. For the calculation of the effects of fault current for a disconnection time up to 5s the value of K is
1. 94
2. 115
3. 197
4. 88
Protective devices against undervoltage are selected as follows except
1. Voltage harmonics
2. Indirect operating undervoltage release
3. Automatic re-closing when the voltage is restored
4. Direct operating undervoltage release
A firefighter's switch shall be installed at a height from the ground not more than 2.75m with
1. ON and OFF positions in letters not less than 10mm high
2. Labelling visible
3. The unit coloured yellow
4. lockable ON position
A cable coupler shall be arranged so that the connector of the coupler is fitted to
1. The end of the cable remote from the supply
2. A system providing mechanical protection
3. The supply side of the circuit
4. A system that is protected by a fuse
Where a residual current monitor RCM is installed downstream of an RCD the RCM is recommended to have a rated residual actuating current not exceeding
1. 0.5 of the RCD
2. 0.66 of the RCD
3. 0.33 of the RCD
4. Tth rated value for the RCD
A detailed inspection of an installation prior to testing is required to verify that installed equipment is satisfied all except
1. Suitable for minimum test values
2. Correctly selected and erected
3. In compliance with Section 511
4. Not visibly damaged or defective
Which one of the following is not characteristic of the supply
1. The nature of fault and harmonic current
2. Frequency
3. Earth fault loop impedance external to the consumer's TN installation
4. Prospective short-circuit current
The connecting cable to a caravan pitch socket-outlet shall be with an allowance of 2m a maximum continuous length of
1. 25m
2. 15m
3. 10m
4. 35m
For high density livestock rearing life support system shall take into account all except
1. Means of monitoring peak energy demand
2. A secure source of back-up supply
3. Temperature and supply voltage monitoring where power ventilation is necessary
4. Selectivity of the main circuits supplying ventilation
For thermosetting insulated cable buried direct in the ground with an ambient temperature of 10 degC the appropriate rating factor to be used is
1. 1.07
2. 1.02
3. 1.12
4. 0.9
For a ring final circuit protected by 32A overcurrent protective device BS 7671 states as a rule of thumb that the total floor area being served is limited to
1. 100 metres squared
2. 75 metres squared
3. 50 metres squared
4. 125 metres squared
Diversity can be considered in a circuit which is
1. Not expected to be fully loaded continually
2. Carrying it's maximum load continually
3. Supplying night operating storage heaters
4. Not in constant use as designed to be a back-up supply circuit
When deciding on the frequency of maintaining an installation during it's intended life which one of the following is not essential requirement
1. The reliability of equipment should have a life of at least 10 years
2. Any protective measures for safety remain effective and not diminished
3. The person or body responsible for the operation/maintenance shall be consulted
4. Any periodic inspection and testing may be readily and safely carried out
For a bare (105 degreeC) M.I cable operating in an ambient temperature of 50 degC the rating factor Ca to be used is
1. 0.84
2. 0.8
3. 0.75
4. 0.91
Testing by the method of simulating a fault condition would be used when testing
1. An RCD
2. Earth electrode resistance
3. Insulation of non-conducting floor
4. Insulation resistance
When it's not reasonably practicable to disconnect surge protective devices when testing insulation resistance the test voltage used for a 230V circuit and the minimum acceptable value of insulation resistance is
1. 250V DC 1M ohms
2. 250V DC 0.5M ohms
3. B 250V DC 0.1M ohms
4. 500V DC 0.5M ohms
In Zone 3 of a hot air sauna equipment must withstand a minimum temperature of 125degC while insulation and sheaths of cables must withstand a minimum temperature of degC
1. 170
2. 150
3. 165
4. 155
For marinas and seashore locations the minimum degree of protection for equipment installed on a pier against water slashes and ingress of small objects is
1. IPX4 and lP3X
2. IPX6 and IP3X
3. IPX4 and IP2X
4. IPX6 and IP2X
For energy efficiency the designer should take into account all the following except
1. Efficiency of protective devices
2. Reduction of energy losses
3. Use of energy
4. Load energy profile
In locations where there are risks of fire due to the nature of processed or stored materials the enclosures of electrical equipment shall be prevented from exceeding under fault conditions the temperature degC is
1. 115
2. 95
3. 85
4. 100
For a 400V installation with Category III equipment the required minimum rated impulse voltage in kV for overload protection is
1. 6
2. 2.5
3. 10
4. 4.0
Copper conductors between Type 1 SPDs and the OCPDs to live conductors shall have c.s.a not less than
1. 6 mmsq
2. 10 mmsq
3. 16 mmsq
4. 4 mmsq
When selecting a SPD for protection which one of the following is not a parameter to be considered
1. Earth leakage current
2. Voltage protection level
3. Continuous operating voltage
4. Nominal discharge current
A steel earthing conductor is buried in soil. It is neither protected against corrosion or mechanical damage. It's minimum cross-sectional area shall be
1. 50 mmsq
2. 40 mmsq
3. 35 mmsq
4. 25 mmsq
Supplementary bonding conductors without mechanical protection connecting exposed or extraneous-conductive parts shall have a minimum c.s.a. of
1. 4 mmsq
2. 2.5 mmsq
3. 6 mmsq
4. 1.5 mmsq
the CENELEC European standards harmonization, for post 1995, sets the permitted tolerance of voltage at
1. +10%/-6%
2. +10%/-10%
3. +6%/-6%
4. +6%/-10%
Emergency lighting shall comply with the following BS standard
1. BS5266
2. BS3676
3. BS5839
4. BS7375
Fire Alarm systems shall comply with the following BS standard
1. BS5839
2. BS3676
3. BS5266
4. BS7375
Relating to technical issues for Prosumer electrical installations, combined short circuit protection shall take account of all possible fault current magnitudes except
1. Conductor insulation values
2. Various operating modes
3. Location of fault
4. Possible combinations of power supplies
A building having the shape and dimensions which facilitate the spread of fire has a classification
1. CB2
2. BE1
3. BA1
4. CA2
A single-pole switching device may switch only the neutral conductor for
1. Connection of a lighting control device
2. PELV circuits
3. RCD protected circuits
4. SELV circuits
Means for emergency switching off shall be
1. One single action
2. Appropriately coloured
3. Clearly labelled
4. Resettable
BS 7671 defines gangways with restricted access as having all except
1. Yellow warning markings
2. Marking by appropriate signs
3. Doors which allow easy evacuation
4. No access to unauthorised persons
To which one of the following AC circuits does a maximum disconnection time of 5s apply
1. TN-C-S system 230v 40A circuit
2. TT system 400v 32A circuit
3. TT system 230v 6A circuit
4. TN-S system 400v 16A
To which one of the following AC circuits does a maximum disconnection time of 1s apply
1. TT system 16A distribution circuit
2. TT system 230v 16A circuit
3. TN-C-S system 63A distribution circuit
4. TN-S system 400v 16A
To which one of the following AC circuits does a maximum disconnection time of 0.4s apply
1. TN-S system 230v 16A circuit
2. TT system 230v 32A circuit
3. TN-C-S system 63A distribution circuit
4. TN-S system 400v 40A circuit
To which one of the following AC circuits does a maximum disconnection time of 0.2s apply
1. TT system 230v 16A circuit
2. TN-C-S system 230v 32A socket circuit
3. TN-C-S system 63A distribution circuit
4. TN-S system 230v 16A circuit
The cross-sectional area of conductors shall be determined by each of the following except
1. The earthing system
2. The maximum temperature
3. The electromagnetic stresses
4. The admissible voltage drop
BS 7671 states the nature of demand is determined by knowledge of all except
1. Averaged hourly demand
2. Daily and yearly variation of demand
3. Special conditions (harmonics)
4. Anticipated future demand if specified
An accessory with female contacts attached to the end of a flexible cable remote from the supply is known as
1. Connector
2. Plug
3. Electrode
4. Adaptor
Agricultural and horticultural premises as defined in BS 7671 include all except
1. Farmhouse
2. Cattle sheds
3. Greenhouses
4. Animal products storeroom
Which one of the following is not characteristic of the supply for a installation
1. The earth fault loop impedance of a TN system
2. External Impedance
3. The prospective short-circuit current at the origin of the installation
4. The nature of the current and frequency
Which one of the following is not an appropriate source for safety services
1. Fused spur on a ring circuit
2. Primary cells
3. Storage batteries
4. Separate independent electrical supply feeder
When protecting against undervoltage any delay in the opening or re-closing of a contactor shall not impede instantaneous disconnection by
1. A control device or a protective device
2. A surge device
3. Discrimination
4. A manual isolator
Where particular risks of fire exist due to the nature of stored materials and in the presence of dust, every luminaire shall be provided with an enclosure
1. With a degree of protection of at least IP5X
2. Class 2 rating
3. With a degree of protection of at least IP4X
4. Class 1 rating
A device not suitable for emergency switching is
1. Plug and Socket
2. Remote control of Circuit breakers
3. Manually operated switching devices
4. Combination of single action devices
For Prosumer installations combined short-circuit protection, the designer must take all the following into account excluding
1. use of the installation
2. location of the fault
3. combination of power supplies connected
4. various operating modes
In Prosumer installations, readings taken with an Earth Fault Loop Impedance tester may be adversely affected by which on of the following specific items of equipment
1. Inverters
2. electric car chargers
3. large motors
4. electric power meters
Determination of Ring and Radial circuit arrangements can be found in Appendix
1. 15
2. 14
3. 11
4. 10
A two-core 4.0mmsq 70 degC thermoplastic insulated armoured cable is installed using reference method C, supplying 230V 30A with circuit of length 10 metres. The calculated voltage drop is
1. 3.3v
2. 6.5v
3. 3.8v
4. 6.9v
For energy efficiency the designer should consider all of the following except
1. Time efficiency during installation
2. Determination of load profile
3. Power factor correction
4. Cross-sectional area of conductors
For the classification of external influences, the code for Fauna hazard is
1. AL2
2. CB2
3. AN2
4. AM2
For a bathroom, supplementary protective equipotential bonding may be installed in the bathroom
1. Either inside or outside preferably close to the point of entry of extraneous-conductive parts
2. Shall not be installed with a RCD protected circuit
3. Only inside
4. Only outside
For a PV system, a Type 1 SPD Impulse current shall be
1. not less than 12.5kV
2. less than 125kV
3. less than 12.5kV
4. more than 125kV
Every installation before being put into service should be given a
1. Inspection and test to verify compliance with regulations
2. Appropriate range of tests
3. Test for insulation resistance
4. Visual inspection

Based on C&G2382 - BS7671:2018 (Amendment 2:2022) Electrical Regulations Mock Exam (30 questions - 60 minute time limit)

BS7671 Electrical regulations mock test (use Amendment 2:2022 regs book) - 30 questions from a large question bank (to be completed within 60 minutes time limit). Regs book answer locations shown in feedback, (hint often provided if you choose wrong answers).