WorksheetsBS 7671 Practice Paper 6
Total questions: 35
Worksheet time: 18mins
Conductors shall be identified in accordance with? Mark one answer.
Section 512
Section 513
Section 514
Section 515
BS 7671 may need to be supplemented by the requirements or recommendations of which other document when applied to electric surface heating systems? Mark one answer.
BS EN 12954
BS EN 13174
BS EN 13636
BS EN 60335-2-96
BS 7671 includes requirements for? Mark one answer.
Electric fences installed on farm-land
Lift installations in office blocks
Wiring systems and cables not specifically covered by the standards for appliances
Wiring systems on military aircraft
BS 7671 is? Mark one answer
Non-statutory and cannot be used as evidence to show compliance, in a court-of-law
Non-statutory but can be used as evidence to claim compliance with a statutory requirement in a court-of-law
Statutory and can be used as evidence to show compliance, in a court-of-law
Statutory and cannot be used as evidence to show compliance, in a court-of-law
What is this statement a definition of: 'Protection against electric shock under fault-free conditions'? Mark one answer
Basic Protection
Direct contact
Fault protection
Indirect contact
Where can further information on Zx be found? Mark one answer.
Appendix 13
Appendix 4
Part 2
Part 3
Regarding the general supply characteristics, which of the options below is not required to be specified by calculation, determination, measurement, enquiry or inspection? Mark one answer.
Nature of the current and frequency
The current-carrying capacities of the cables
The prospective short-circuit current at the origin of the installation
The type and rating of the overcurrent protective device
EMC regulations are referred to in BS 7671, what does EMC refer to? Mark one answer.
Earthed Magnetic Compatibility
Electrical Magnetic Compatibility
Electromagnetic Compatibility
Electronic Magnetic Compatibility
To ensure an economic and reliable design, what should be determined? Mark one answer.
Earthing arrangement
Maximum cable length
Maximum demand
The nature of the current and frequency
Which of the following is an assessment of the compatibility of characteristics, of equipment used? Mark one answer.
Continuity of service
Maintainability
Power factor
Purpose, supplies and structure
Which of the following is an assessment of general characteristics? Mark one answer.
The current carrying capacity of the conductors
The diversity factor that may be applied
The maximum demand required
The purpose for which the installation is intended to be used
A general hospital operating theatre needs to ensure the electrical supply will not be cut off during critical operations; and as such an assessment for continuity of service must be conducted; which of the following must be considered? Mark one answer.
Multiple power supplies
The emergency backup supply system
The operating theatre equipment reliability
The oxygen supply system feeder-pump
In an area where there is a risk of fire, cables not completely embedded in non-combustible material such as plaster, or protected from flame by some other means shall have the flame propagation characteristics as specified by which one of the following British Standards? Mark one answer.
BS EN 60332-1-2
BS EN 60598-2-24
BS EN 61386-1
BS EN 61537
A single-phase reduced low voltage system has been installed with a 25 amp BS 88-2 fuse, what is the maximum allowable value of Zs? Mark one answer.
0.51 Ω
0.52 Ω
0.63 Ω
0.81 Ω
Chapter 43 of BS 7671 provided protection against? Mark one answer.
Overcurrent
Overvoltage
Undercurrent
Undervoltage
The method of protection by use of non-conducting locations is? Mark one answer.
Not recognised for general application
Regularly used throughout commercial installation
Used wherever water is present such as marinas
Usually reserved for travelling fairgrounds and circuses
When selecting a device for overload protection, the device must be co-ordinated with the conductor to ensure?
The continuous service current of the cable is 1.45 times higher than the current causing the overload
The current I₂ causing effective operation of the protective device does not exceed 1.45 times the lowest of the current-carrying capacities Iz of any of the conductors of the circuit
The design current of the circuit is less than the rated current of the protective device
The rated current of the protective device exceeds the lowest rated capacity of any cable
Which of these is not an example of an extraneous-conductive part? Mark one answer.
Central heating radiator
Exposed metallic structural part of a building
Metal trunking enclosing cables
Water pipe feeding a gas boiler
Where the transfer of supply to an alternative supply is to take place in a TN system, a multi-pole switch must be used which switches the line and neutral conductors, this method prevents? Mark one answer.
Electromagnetic fields due to stray currents in the main supply system
The earth-fault loop impedance exceeding maximum values
The prospective fault current tripping the main protective circuit breaker
The rated residual current tripping any RCD devices
Simultaneously accessible exposed-conductive parts shall be connected to the same earthing system? Mark one answer
Independent of each system
Individually, in groups or collectively
Not at all
Through a high resistance impedance
What is the minimum impulse voltage for 120 V Category II equipment? Mark one answer
1.5 kV
2.5 kV
4.0 kV
6.0 kV
Where a building is mainly constructed of combustible material e.g. wood
Where a building is mainly constructed of combustible material e.g. wood
Where a building is subject to ground tremors
Where a building is subjected to extreme ultra-violet radiation
Where a building is subjected to heavy water waves
The figure below shows a substation connection diagram, what does U₂ represent? Mark one answer
A rock band
Power frequency fault voltage that appears in the low voltage system between exposed conductive parts and earth for the duration of a fault
Power frequency stress voltage between the line conductor and the exposed conductive parts of the equipment of the low-voltage installation during the fault
Power frequency stress voltage between the line conductor and the exposed conductive parts of the low-voltage equipment of the transformer substation during the fault
In an IT system that does not have a neutral conductor, it is permitted to omit a device to provide overload protection if? Mark one answer.
An RCD is installed in each circuit
Harmonic currents will not be present
The DNO supply fuse will provide this protection
The IT earth-impedance is sufficiently high enough
A BS 88-2 fuse is to be fitted to a TN circuit with a Zs value of 2.4 Ω and requiring a disconnection time of 0.4s. What is the maximum rated fuse that could be used? Mark one answer.
16 A
20 A
25 A
32 A
A temperature cut-out device shall have only? Mark one answer
A manual reset
A master reset
A re-settable reset
An automatic reset
A circuit consists of 35 mm² copper conductors protected by 90°C thermoplastic insulation, the conductors have an initial temperature of 90°C and a final temperature of 160°C, related to the formula below what is the value of k? Mark one answer
68
93
100
143
A client requires a lighting system to be installed in a 'pelmet', with regards to this type of installation BS 7671 stipulates that "There shall be"? Mark one answer
No adverse effects due to the presence of curtains
No adverse effects due to the presence of heat
No adverse effects due to the presence of sunlight
No adverse effects due to the presence of wall-paper
Where identification of individual conductors is made by use of numerals, what colour ratio is permitted for the identification? Mark one answer.
Black on Brown
Black on White
Red on Black
Yellow on Brown
A generating set is to run in parallel with the public supply system, which of the following factors need NOT be taken into consideration? Mark one answer
Earth fault loop impedance
Harmonic distortion
Power factor
Voltage changes
Where water may collect or condensation may form in a wiring system, provision shall be made for? Mark one answer
Effects of corrosion
Its escape
Short circuits
Ventilation
What specific function can an electrical device provide, if the symbol shown below is marked on the device? Mark one answer.
All the above
Emergency switching
Functional switching
Isolation
What type of protection is provided in the following image? Mark one answer.
Overload protection
Short-circuit protection
Surge protection
Undervoltage protection
34. What information needs to be shown on an Electrical Installation Condition Report notification label? Mark one answer
Date of last inspection
Installation details
Name of tester
Results of inspection
35. A circuit is installed with 10 mm² 70℃ thermoplastic multicore cable which has a protective conductor made of copper. The maximum fault current that can occur in the circuit is 600 amps, which will disconnect the circuit in 0.1 seconds, what is the minimum acceptable cross-sectional area of the cpc? Mark one answer
1.0 mm²
1.5 mm²
2.5 mm²
4.0 mm²
