MOCK EXAM from past papers - No. 1

16. An overload current is classified as an overcurrent occurring in a circuit which
a. is electrically sound
b. has a fault between line conductors
c. has a fault between a line conductor and neutral
d. has a fault between neutral and earth

17. BS 7671 is designed to provide
a. instruction for untrained persons
b. safety especially from fire, shock and burns
c. a detailed specification
d. instructions for every circumstance in an installation

18. Which one of the following is not permitted as a means of isolation in a circuit?
a. Double pole switch
b. 13A plug and socket
c. Semi-conductor device
d. Linked switch

19. When a line conductor comes in contact with a neutral conductor the type of fault is
a. a short-circuit fault
b. an earth fault
c. an overload fault
d. an open circuit fault

20. A means of isolation must be provided in an electrical installation. This is required to be
a. clearly identified
b. always placed next to the equipment it isolates
c. automatic in operation
d. available for emergency switching

21. To comply with BS 7671 a firefighter's switch should be
a. fixed 3.75m above the ground with the off position at the top
b. coloured red with the off position at the bottom
c. coloured red and be fixed 2.75m from the ground
d. fixed 2.75m from the ground with the off position at the bottom

22. A firefighter's emergency switch should be provided for
a. emergency lighting systems operating at low-voltage
b. interior low-voltage discharge lighting installations
c. exterior discharge lighting installations exceeding low-voltage
d. fire alarm circuits operating above low voltage

23. The three general characteristics of external influence are environment, utilisation and
a. the number and type of live conductors
b. construction of buildings
c. method of installation
d. the installation earthing arrangements

24. BS 7671 details the requirements for switching off for mechanical maintenance. Which of the following devices would not satisfy these requirements?
a. A control switch operating a contactor
b. A circuit breaker
c. A 32A plug and socket outlet
d. A multipole switch

25. Which one of the following is required to be considered when assessing the general characteristics of an electrical installation?
a. The electrician's qualifications
b. Diversity
c. Switchgear rating
d. Maintainability

26. On agricultural premises, an RCD may be used for protection against fire providing the operating current does not exceed
a. 30mA
b. 100mA
c. 300mA
d. 500mA

27. When calculating the voltage drop in an electrical installation, which one of the following must be taken into account?
a. The current carrying capacity of the cable
b. The operating current of the fuse
c. The current rating of the fuse
d. The design current of the circuit

28. Which one of the following is not considered when calculating the minimum current carrying capacity of live conductors of a cable?
a. Ambient temperature
b. Grouping
c. Type of protective device
d. The maximum permitted volt drop

29. For single circuit cable selection, the correction factors must be applied to the
a. prospective short-circuit current
b. current carrying capacity of the cable
c. current rating of the protective device
d. earth fault current of the circuit

30. The classification code for high wind is
a. AS3
b. AR3
c. AP3
d. AN3