Deck 3: Principles of Electrical Science

Question 1

An appropriate wiring method for a high-temperature installation in a boiler house is:

A) metal conduit installation
B) trunking and tray installation
C) FP200 cables
D) MI cables.

Answer 1

FP200 cables
MI cables.

Question 2

Which of the following fixing methods would be suitable for securing a heavy electric motor to a concrete bed?

A) cable clip
B) Rawlbolt
C) screw fixing to plastic plug
D) spring toggle.

Answer 2

Rawlbolt

Question 3

Which of the following fixing methods would be suitable for holding a PVC insulated and sheathed cable onto a wood surface such as a ceiling joist?

A) cable clip
B) Rawlbolt
C) screw fixing to plastic plug
D) spring toggle.

Answer 3

cable clip

Question 4

Which of the following fixing methods would be suitable for holding a medium-weight load onto a brick wall?

A) cable clip
B) Rawlbolt
C) screw fixing to plastic plug
D) spring toggle.

Question 5

Which of the following fixing methods would be suitable for holding a lightweight load on a plasterboard partition?

A) cable clip
B) Rawlbolt
C) screw fixing to plastic plug
D) spring toggle.

Question 6

A PVC conduit installation would be suitable for the following type of installation:

A) commercial
B) domestic
C) horticultural
D) industrial.

Question 7

A PVC insulated and sheathed wiring system would be suitable for the following type of installation:

A) commercial
B) domestic
C) horticultural
D) industrial.

Question 8

The protection provided by protective equipotential bonding and automatic disconnection of the supply is called:

A) overload protection
B) short-circuit protection
C) basic protection
D) fault protection.

Question 9

The protection provided by insulating the live parts of the electrical installation is called:

A) overload protection
B) short-circuit protection
C) basic protection
D) fault protection.

Question 10

The gas, water and central heating pipes of the building not forming a part of the electrical installation are called:

A) earth conductors
B) bonding conductors
C) exposed conductive parts
D) extraneous conductive parts.

Question 11

The conduit and trunking parts of the electrical installation are:

A) earth conductors
B) bonding conductors
C) exposed conductive parts
D) extraneous conductive parts.

Question 12

The linking together of the exposed or extraneous conductive parts of an installation for the purpose of safety is one definition of:

A) earthing
B) protective equipotential bonding
C) exposed conductive parts
D) extraneous conductive parts.

Question 13

The connection of the exposed conductive parts of an installation to the main protective earthing terminal of the installation is one definition of:

A) earthing
B) protective equipotential bonding
C) overload
D) short circuit.

Question 14

A scale drawing which shows the original intention for the position of electrical equipment is called a:

A) wiring diagram
B) detail assembly drawing
C) site plan or layout drawing
D) as-fitted drawing.

Question 15

A scale drawing which shows the actual position of the electrical equipment upon completion of the contract is called a:

A) wiring diagram
B) detail assembly drawing
C) site plan or layout drawing
D) as-fitted drawing.

Question 16

A steel trunking installation would be suitable for the following type of installation:

A) commercial
B) domestic
C) horticultural
D) industrial.

Question 17

A steel conduit installation would be suitable for the following type of installation:

A) commercial
B) domestic
C) horticultural
D) industrial.

Question 18

Electricity is distributed from the local substations by underground cables at:

A) 230 V
B) 400 V
C) 25 kV
D) 132 kV.

Question 19

Electricity is transmitted at very high voltages because for a given power the:

A) current is reduced
B) current is increased
C) losses are reduced
D) losses are increased.

Question 20

An appropriate wiring system for a three-phase industrial installation would be:

A) PVC cables
B) PVC conduit
C) one which meets the requirements of Part 2 of the IET Regulations
D) one which meets the requirements of Part 5 of the IET Regulations

Question 21

The cables suspended from the transmission towers of the National Grid network are made from:

A) aluminium and porcelain.
B) copper and brass
C) copper with PVC insulation
D) aluminium and steel

Question 22

An appropriate wiring method for an underground feed to a remote building would be a:

A) metal conduit installation
B) trunking and tray installation
C) PVC cables
D) PVC/SWA cables

Question 23

An appropriate wiring method for a domestic installation would be a:

A) metal conduit installation
B) trunking and tray installation
C) PVC cables
D) PVC/SWA cables

Question 24

An electrical cable is made up of three parts which are:

A) conduction, convection and radiation
B) conductor, insulation and outer sheath
C) heating, magnetic and chemical
D) conductors and insulators.

Question 25

A diagram which shows most clearly how a circuit works, with all items represented by graphical symbols, is a description of a:

A) block diagram
B) site plan or layout diagram
C) wiring diagram
D) circuit diagram.

Question 26

A diagram which shows the detailed connections between individual items of equipment is a description of a:

A) block diagram
B) site plan or layout diagram
C) wiring diagram
D) circuit diagram.

Question 27

A scale drawing showing the position of equipment by graphical symbols is a description of a:

A) block diagram
B) site plan or layout diagram
C) wiring diagram
D) circuit diagram.

Question 28

An over-current resulting from a fault of negligible impedance is one definition of:

A) earthing
B) bonding
C) overload
D) short circuit.

Question 29

A current which exceeds the rated value in an otherwise healthy circuit is one definition of:

A) earthing
B) bonding
C) overload
D) short circuit.

Question 30

An appropriate wiring system for a three-phase industrial installation would be:

A) PVC cables
B) PVC conduit
C) one which meets the requirements of Part 2 of the IET Regulations
D) one which meets the requirements of Part 5 of the IET Regulations

Question 31

According to IET Regulation 411.3.2.2 all final circuits not exceeding 32 A in a building supplied with a 230 V TN supply shall have a maximum disconnection time not exceeding:

A) 0.2 s
B) 0.4 s
C) 5.0 s
D) unlimited.

Question 32

The weakest link in the circuit designed to melt when an over-current flows is one definition of:

A) fault protection
B) a circuit protective conductor
C) a fuse
D) a consumer unit.

Question 33

A current which exceeds the rated current in an otherwise healthy circuit is one definition of:

A) fault protection
B) an over-current
C) an overload current
D) a short-circuit current.

Question 34

Cutting off the electrical supply in order to ensure the safety of those working on the equipment is one definition of:

A) basic protection
B) fault protection
C) equipotential bonding
D) isolation switching.

Question 35

The protection provided by equipotential bonding and automatic disconnection of the supply is called:

A) extraneous conductive parts
B) basic protection
C) exposed conductive parts
D) fault protection.

Question 36

The metalwork of the building and other service pipes is called:

A) extraneous conductive parts
B) basic protection
C) exposed conductive parts
D) fault protection.

Question 37

The metalwork of the electrical installation is called:

A) extraneous conductive parts
B) basic protection
C) exposed conductive parts
D) fault protection.

Question 38

The protection provided by insulating live parts is called:

A) extraneous conductive parts
B) basic protection
C) exposed conductive parts
D) fault protection.

Question 39

The act of linking together the exposed and extraneous metal parts is called:

A) earthing
B) bonding
C) basic protection
D) fault protection.

Question 40

The act of connecting the exposed conductive parts of the installation to the main earthing terminal of the installation is called:

A) earth
B) earthing
C) bonding conductor
D) circuit protective conductor.

Question 41

A protective conductor connecting exposed and extraneous parts together is one definition of:

A) earth
B) earthing
C) bonding conductor
D) circuit protective conductor.

Question 42

A protective conductor connecting exposed conductive parts of equipment to the main earthing terminal is one definition of:

A) earth
B) earthing
C) bonding conductor
D) circuit protective conductor.

Question 43

To ensure the effective operation of the over-current protective devices, the earth fault loop path must have:

A) a 230 V supply
B) a very low resistance
C) fuses or MCBs in the live conductor
D) a very high resistance

Question 44

Electricity is generated in large commercial power-stations at:

A) 230 V
B) 400 V
C) 25 kV
D) 132 kV.

Question 45

The cables suspended from the transmission towers of the National Grid network are made from:

A) copper and brass
B) copper with PVC insulation
C) aluminium and steel
D) aluminium and porcelain.

Question 46

An appropriate wiring method for a high-temperature installation in a boiler house is:

A) metal conduit installation
B) trunking and tray installation
C) FP 200 cables
D) MI cables.

Question 47

An appropriate wiring method for an underground feed to a remote building would be a:

A) metal conduit installation
B) trunking and tray installation
C) PVC cables
D) PVC/SWA cables.

Question 48

An appropriate wiring method for a domestic installation would be a:

A) metal conduit installation
B) trunking and tray installation
C) PVC cables
D) PVC/SWA cables.

Question 49

An electrical cable is made up of three parts which are:

A) conduction, convection and radiation
B) conductor, insulation and outer sheath
C) heating, magnetic and chemical
D) conductors and insulators.

Question 50

The phase current of a delta-connected load is 100 A. The line current will be:

A) 57.73 A
B) 101 A
C) 173.2 A
D) 231 A.

Question 51

The phase current of a star-connected load is 100 A. The line current will be:

A) 57.73 A
B) 100 A
C) 173.2 A
D) 230 A.

Question 52

The phase voltage of a delta-connected load is 100 V. The line voltage will be:

A) 57.73 V
B) 101 V
C) 173.2 V
D) 231 V.

Question 53

The phase voltage of a star-connected load is 100 V. The line voltage will be:

A) 57.73 V
B) 100 V
C) 173.2 V
D) 230 V.

Question 54

A load connected to phase and neutral of a star-connected three-phase four-wire supply system from the local substation would have a voltage of:

A) 230 V
B) 400 V
C) 25 kV
D) 132 kV.

Question 55

A load connected to the three phases of a star-connected three-phase fourwire supply system from the local substation would have a voltage of:

A) 230 V
B) 400 V
C) 25 kV
D) 132 kV.

Question 56

Transmission of electricity on the National Grid network takes place at:

A) 230 V
B) 400 V
C) 25 kV
D) 132 kV.

Question 57

'The conductive mass of the earth' is one definition of:

A) earth
B) earthing
C) bonding conductor
D) circuit protective conductor.