GMJ 6035 Mock Science

Which one of the following materials expands the MOST when heated?

• Copper

• Steel

• PVC

• Lead

Which one of the following materials is an alloy?

• Brass

• Zinc

• Lead

• Copper

Which one of the following types of stress is applied to a solid material to test the tensile strength breaking point?

• Pulling

• Twisting

• Squashing

• Resonating

Which one of the following indicates the correct unit of measurement for the specific heat capacity of a material?

• Kg/m³

• M²/°C

• kJ/kg

• kJ/kg/°C

The formula for calculating linear expansion is material length x coefficient of linear expansion x temperature rise. Copper has a coefficient of linear expansion of 0.000016. If the temperature rise of the pipework is 20°C, how much does 10 metres of copper pipework expand by?

• 16mm

• 1.6mm

• 3.2mm

• 32mm

A coil within a cylinder transfers heat by which of the following methods?

• Radiation

• Conduction

• Convection

• Resistance

‘Capillary action’ may be the cause of which one of the following systems faults?

• Air into a radiator

• Loss of trap seal

• Expansion of system water

• Leak on a soldering fitting

‘Capillary action’ can be utilised in which one of the following processes?

• Soldering copper fittings

• Soldering welding fittings

• Threading pipework

• Pop riveting

In the electromotive series, which one of the following metals is the most cathodic?

• Magnesium

• Aluminium

• Chromium

• Copper

The best method to prevent corrosion in a wet central heating system is to use:

• Electronic water conditioners

• High pressure pumping

• Chemical additives

• Oxygenated water