Key plumbing principles

Which one of the properties of water is shown by its pH value?

• It’s degree of acidity or alkalinity.

• It’s electrical conductivity

• The amount of heat it contains.

• It’s heat conductivity

Capillarity in liquids may occur between two close fitting surfaces

• When the surfaces are in a horizontal or vertical position

• Only when the surfaces are at an angle of 45 degrees

• Only when the surfaces are at an angle of less than 30 degrees

• Only when the surfaces are in a horizontal position

Given that all holes have the same diameter, the water pressure is greatest at hole

• A

• B

• C

• D

The process of siphonage utilises

• Vacuum pumps.

• Capillary action

• Atmospheric pressure

• Specific gravity

• Water pressure

Capillary attraction would be greatest in tube

• A

• B

• C

• D

Relative density is the

• Density of a substance divided by its volume

• Density of a substance in comparison to the density of water

• Density of water displaced when a substance is placed in water

• Force exerted by the density of a substance

Which one of the following metals needs to be treated if it is exposed to the effects of atmospheric corrosion?

• Iron.

• Galvanised steel.

• Lead.

• Zinc.

During electrolytic action the

• Anode will gradually destroy the cathode

• Cathode will gradually destroy the anode

• Electrolyte will be used up and disappear

• Electrolyte will destroy the cathode

Socket outlets in a domestic property usually have a maximum amp rating of

• 6 Amps

• 5 Amps

• 13 Amps

• 3 Amps

It would be most appropriate for a plumber to use temporary earth continuity bonds when

• Flushing a domestic hot water system

• Working on a central heating control panel

• Changing a cold water tap washer

• Removing a section of system pipework