Thermal expansion & corrosion of materials

What is the coefficient of linear expansion used to measure?

• The color change of a material when heated

• The weight of a material when heated

• The amount a material expands when heated

• The density of a material when heated

Why must plumbers consider the expansion of materials?

• To ensure the pipes are colorful

• To prevent water from freezing

• To avoid creaking and damage

• To make the pipes lighter

What can cause plastic guttering to expand?

• Cold weather

• Sunlight

• High pressure

• Low humidity

What is the coefficient of linear expansion for Plastic uPVC?

• 0.00018

• 0.00029

• 0.000016

• 0.000011

If a 6 metre length of plastic guttering expands by 0.0108m, what was the temperature rise?

• 10°C

• 5°C

• 15°C

• 20°C

Which material has the highest coefficient of linear expansion?

• Lead

• Plastic uPVC

• Copper

• Steel

How much will a 6 metre length of steel expand if the temperature rises by 10°C?

• 0.00066m

• 0.00108m

• 0.00011m

• 0.00018m

What factors can affect the amount and speed of corrosion in materials?

• Wet conditions, gases, dissimilar metals, acids, heat, UV

• Dry conditions, sunlight, plastic, cold, wind

• Only wet conditions and heat

• Only gases and UV

What is the most common form of corrosion?

• Galvanization

• Rust (Oxidation)

• Tarnishing

• Patina

What elements are necessary for rust to occur?

• Water, iron, and nitrogen

• Water, iron, and oxygen

• Water, copper, and oxygen

• Water, aluminum, and oxygen