Which pipe, measuring 6m in length, will offer the greatest resistance to the flow of water?

• 15mm pipe with four elbows

• 15mm pipe with four machine bends

• 22mm pipe, reduces down to 15mm halfway along its length

• 15mm pipe with two machine bends and two elbows

Conduction occurs by

• Heat travelling in a straight line through the air

• Heat travelling through or along a solid material

• Heat travelling via a chemical reaction

• Heat travelling via the motion of a fluid

What is this symbol for?

• DC electricity

• System circulator

• Electrical resistance

• AC electricity

Which of the following will cause siphonage to occur?

• Suction at point C

• Increase in pressure at point B

• Suction at point A

• Atmospheric pressure in the tube

What is the freezing point of water at sea level?

• 100°C

• 75°C

• 25°C

• 0°C

Which of the following materials is the best conductor of heat?

• Lead

• Low carbon steel

• Copper

• Cast iron

What would the fuse size be for a domestic appliance that has a power rating of 3kW?

• 13 amp

• 10 amp

• 5 amp

• 3 amp

Which of the following values reflects the pH value for pure water?

• 1

• 4

• 7

• 11

The limescale build-up in systems is caused by?

• Soft water

• Acidic water

• Temporary hard water

• Permanently hard water

This form of corrosion is generally caused by?

• Flux left in the tube after flushing out

• The inhibitor in the system being too strong

• Position of the electrolytic series table

• Bad manufacture