Wiring Systems, Conductors and Insulators
Cable types, design, limitation and use - 10 questions from a bank of questions
Answer ALL questions. Look for any feedback given if you get an answer incorrect. Keep choosing an answer until you get it correct. CORRECT or INCORRECT answers are indicated at the TOP of the page. A score is given at the TOP of the page when the exercise has been completed. © K.Brown 2015
What cable size is usually used in a domestic lighting circuit ?
- 6.0sqmm
- 1.5sqmm
- 10sqmm
- 2.5sqmm
What are the three colours found inside a 3-core and earth cable (i.e. for 2-way and intermediate lighting circuit) ?
- red, yellow, blue
- brown, black, grey
- brown, blue, black
- brown, grey, blue
What are the three colours used for the live (line) conductors of a 3-phase cable ?
- red, yellow, blue
- brown, black, grey
- brown, blue, black
- brown, grey, blue
What is the name given to the TWO cables that connect two 2-way switches together in a lighting circuit ?
- lives
- strippers
- strappers
- connectors
What size cable is usually used for a 'ring main' of socket outlets in a domestic dwelling ?
- 1.5sqmm
- 2.5sqmm
- 3.0sqmm
- 6.0sqmm
What colour is a live (line) conductor in a single phase supply?
- brown
- blue
- black
- grey
What colour is a neutral conductor in a single phase supply?
- brown
- blue
- black
- grey
By what means are the black and grey 'switched lives' in a 2-way and intermediate lighting circuit identified ?
- fit brown sleeving/marker
- fit red sleeving/marker
- fit blue sleeving/marker
- fit grey sleeving/marker
When terminating a cable into an accessory, it is good practice to ensure the sheathing is...........
- left 15mm outside the accessory
- completely removed
- taken at least 5mm into the accessory
- exactly level with the edge of the accessory
Which one of the following is not a conductor ?
- brass
- air
- steel
- mercury
What is the internal insulating medium (material) in a M.I cable ?
- manganese oxide
- magnesium oxide
- magnesium oxate
- manganese dioxide
Where might you find an 'intermediate' lighting circuit arrangement ?
- a multi-level flight of stairs
- a two door room
- a single storey building
- a short corridor
Which one of the following is not an insulator ?
- oil impregnated paper
- mica
- air
- constantan
What happens to p.v.c insulation if handles at temperatures below zero degrees C ?
- it can be handled ok
- it can easily be damaged at these low temperatures
- it changes colour
- it can be installed but cannot have current flow through it until it warms up
What is 'arctic' cable insulation ?
- 'special' PVC insulation able to operate/be handled at very low temperatures
- 'special' cable for hot environments
- 'special' extra-flexible cable
- 'special' white coloured cable
Which one of the following cable systems provides some heat and chemical-proofing properties?
- PVC/PVC
- PILC
- XLPE
- SWA
Which one of the following cable system is used for underground supply cables in older installations?
- PVC/PVC
- PILC
- XLPE
- SWA
Which one of the following cable system is used for sub-main supply cables in industrial installations?
- PVC/PVC
- PILC
- XLPE
- SWA