Where was the blast furnace developed by Abraham Darby?

• London

• Coalbrookdale

• Manchester

• Birmingham

What is the role of manganese in plain-carbon steel?

• It increases corrosion resistance

• It offsets the harmful effects of impurities

• It makes the steel more flexible

• It reduces the cost of production

Which element in plain-carbon steel is responsible for its hardness?

• Iron

• Carbon

• Sulphur

• Phosphorus

What is the typical carbon content in low-carbon steels?

• Up to 0.1%

• Up to 0.3%

• Up to 0.5%

• Up to 0.7%

Which property is more important for steels used in sprockets and springs?

• Toughness

• Wear properties

• Flexibility

• Color

For what purpose are steels with carbon content above 0.9% used?

• Decorative items

• Hand and cutting tools

• Electrical wiring

• Textile manufacturing

What is a spring collet?

• A type of flower

• A tool for holding objects

• A musical instrument

• A type of fabric

Which impurity might be present in cast iron?

• Gold

• Sulphur

• Copper

• Zinc

Which of the following is a characteristic of compacted graphite iron?

• High thermal conductivity

• Low density

• High electrical resistance

• Low melting point

What makes grey iron suitable for use in valves and fittings?

• High elasticity

• Resistance to chemicals, water, gas, and steam

• High melting point

• Low density