Understand how to apply scientific principles within mechanical services engineering

Level 2 NVQ Diploma in Plumbing and Domestic Heating

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

A. 0ºC.B. 32ºC.C. 75ºC.D. 100ºC.

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

temperatures?A. 25ºC.B. 50ºC.C. 75ºC.D. 100ºC.

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

temperatures?A. 0ºC.B. 4ºC.C. 25 ºC.D. 52 ºC.

What is the intensity of pressure acting on the inlet to the 15 mm tap

shown in the following diagram?

A. 5.88kPa.B. 19.18kPa.C. 39.24kPa.D. 88.29kPa.

Which one of the following pipes of equal length will create the greatest

resistance to the flow of water? A. A 22mm pipe which reduces down to 15mm

for a quarter of its length.B. A 15mm pipe which contains 4 machine

bends.C. A 15mm pipe which contains 2 machine

bends and 2 elbows.D. A 15mm pipe which contains 4 elbows.

Which one of the following will cause siphonage to occur from the upper container to the lower

container in the following diagram?

A.Suction pressure at point B.

B.Positive pressure at point B.

C.Suction pressure at point A.

D.Atmospheric pressure at points A and B.

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

heating system?

A.Cylinder thermostat.B.Room thermostat.C.Differential digital thermometer.D.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?

A. 42000kJ.B. 50400kJ.C. 84000kJ.D. 96000kJ.

Conduction occurs by

A. heat travelling in straight lines through airB. heat travelling through a solid materialC. heat transfer by a chemical reactionD. 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?

A.Radiation.B.Conduction.C.Convection.D.Thermal relaying.

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

a) Copper.b) Lead.c) Low carbon steel.d) Iron.

Which one of the following values reflects a neutral pH?

A. 1.B. 4.C. 7.D. 11.

Lime-scale in hot water is caused by

A. soft waterB. temporarily hard waterC. permanently hard waterD. distilled water.

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

following?

A. The melting point of the metals.B. Their position in the electro-chemical series.C. The relative density of the metals.D. The rate of thermal expansion of the metals.

The following diagram shows a type of metallic roof joint which incorporates a gap in the joint

design. What is the purpose of the gap?

A. To reduce shrinkage of the material.

B. To prevent capillary action.

C. To allow thinner metal to be used.

D. To add insulation to the roof covering.

Which one of the following is a ferrous metal?

A. Copper.B. Brass.C. Low carbon steel.D. Lead.

Which one of the following identifies the coating that forms on the surface of sheet lead and

provides a protective coating?

A. Sulphate.B. Patina.C. Galina.D. Surface sheen.

By how much will a 10 metre length of gutter expand when heated from 15ºC to 30ºC, if the coefficient of

linear expansion of plastic is 0.00018?

A. 13mm.B. 27mm.C. 58mm.D. 107mm.

The SI unit for measuring electrical current is

A. wattB. jouleC. ohmD. ampere.

What is the typical size of fuse that will be required for an 1100 watt portable

appliance fed by a 240 volt supply?

A. 1 amp.B. 3 amp.C. 5 amp.D. 13 amp.