Scientific principles in plumbing Quiz

Which one of the following is the freezing point of water?

• 0°C.

• 32°C.

• 75°C.

• 100°C.

A change of state in water takes place at which of the following temperatures?

• 25°C.

• 50°C.

• 75°C.

• 100°C.

Water is at its maximum density at which one of the following temperatures?

• 0°C.

• 4°C.

• 25°C.

• 52°C.

Which one of the following pipes of equal length will create the greatest resistance to the flow of water?

• A 22mm pipe which reduces down to 15mm for a quarter of its length.

• A 15mm pipe which contains 4 machine bends.

• A 15mm pipe which contains 2 machine bends and 2 elbows.

• A 15mm pipe which contains 4 elbows.

Conduction occurs by

• heat travelling in straight lines through air

• heat travelling through a solid material

• heat transfer by a chemical reaction

• heat transfer by motion of a fluid

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

• Copper

• Lead

• Low carbon steel

• Iron

Which one of the following values reflects a neutral pH?

• 3

• 5

• 7

• 9

Lime-scale in hot water is caused by

• soft water

• temporarily hard water

• permanently hard water

• distilled water

The rate of electrolytic corrosion of metallic materials in a plumbing system is affected by which one of the following?

• The melting point of the metals.

• Their position in the electro-chemical series.

• The relative density of the metals.

• The rate of thermal expansion of the metals.

Which one of the following is a ferrous metal?

• Copper

• Aluminum

• Iron

• Lead