Plumbing Science Quiz 1

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

• 0ºC.
• 32ºC.
• 75ºC.
• 100ºC.

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

• 25ºC.
• 50ºC
• 75ºC.
• 100ºC.

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

• 0ºC
• 4ºC.
• 25 ºC.
• 52 ºC.

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.

Which one of the following types of device is used to take temperature measurements of pipe surfaces when commissioning a central heating system?

• Cylinder thermostat.
• Room thermostat.
• Differential digital thermometer.
• Multi-meter.

What is the amount of heat energy required to raise 200 litres of water from 10ºC to 60ºC, if the specific heat capacity of water is 4.2 kJ/kg/ºC?

• 42000kJ.
• 50400kJ.
• 84000kJ.
• 96000kJ.

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 method of heat transfer is shown in the following diagram by water being heated in the boiler, circulating through pipe A to the cylinder and returning to the boiler for re-heating by pipe B?

• Thermal relaying.
• Convection.
• Conduction.
• Radiation.

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?

• 1.
• 4.
• 7.
• 11