Grade 10 metalwork – Ferrous and Non-Ferrous Metals Quiz
1. Which of the following best defines ferrous metals?
Ferrous metals contain iron (Fe) as a main element and are typically magnetic; examples include cast iron, mild steel and stainless steel (which still contains iron).
2. What is the main characteristic of non-ferrous metals?
Non-ferrous metals (like aluminium, copper and brass) lack significant iron content, are usually non-magnetic and often resist corrosion better than ferrous metals.
3. Which of the following is a ferrous metal commonly used in construction in Kenya?
Mild steel contains iron and carbon and is a ferrous metal widely used in Kenya for rebar, frames and roofing structures due to its strength and affordability.
4. Which of these is a non-ferrous metal often used for cooking pots and pans?
Aluminium is a non-ferrous metal that is lightweight, conducts heat well and is commonly used for cooking utensils and pots.
5. Which metal is most commonly used for electrical wiring in Kenyan houses?
Copper is an excellent conductor of electricity, ductile and widely used for house wiring in Kenya and worldwide.
6. Which metal is most commonly used to make corrugated roofing sheets (known locally as 'corrugated iron')?
Corrugated roofing sheets are usually made from steel sheet that has been galvanised (coated with zinc) to reduce rusting; they are ferrous because the base metal is iron/steel.
7. Which metal is most likely to rust when left unprotected in the rain?
Rusting is the corrosion of iron; ferrous metals such as iron and low-carbon steel form iron oxide (rust) when exposed to moisture and oxygen.
8. Which metal contains chromium and is well known for resisting corrosion in kitchens and workshops?
Stainless steel is an iron-based alloy with chromium (and often nickel) that forms a protective oxide layer, making it resistant to corrosion and suitable for kitchen equipment.
9. Brass is an alloy made from which two metals?
Brass is a non-ferrous alloy composed mainly of copper and zinc; it is used for decorative items, fittings and some musical instruments.
10. Bronze is an alloy traditionally made from which metals?
Bronze is a copper-tin alloy known for good hardness and corrosion resistance and has been used for tools, statues and bearings.
11. Which metal is known for being very malleable and commonly used for lightweight cookware and soda cans?
Aluminium is soft, malleable and lightweight, making it suitable for cookware and beverage cans; it is non-ferrous and resistant to corrosion when anodised.
12. Among commonly used metals, which is the best conductor of electricity for practical wiring?
Copper has excellent electrical conductivity, good ductility and durability, which is why it is the standard for electrical wiring.
13. What simple tool can you use in the workshop to check if a metal is ferrous or non-ferrous?
A magnet is a quick test: ferrous metals (with iron) are usually attracted to a magnet, while most non-ferrous metals are not.
14. Which metal is light and commonly used for making aircraft parts and beverage cans?
Aluminium has a low density, good strength-to-weight ratio and corrosion resistance, so it is widely used in aircraft manufacturing and cans.
15. Which ferrous metal is very hard and is commonly used for making cutting tools and chisels?
High-carbon steel has a higher carbon content that hardens well and can hold a sharp edge, making it suitable for tools and cutting edges.
16. Which non-ferrous metal is commonly used for decorative items and old Kenyan coins because of its gold-like colour?
Brass, an alloy of copper and zinc, has a yellowish, gold-like appearance and is often used for decorative items and some coinage.
17. What metal is used to galvanize steel to protect it from rusting?
Zinc is applied as a coating to steel (galvanising). It acts as a sacrificial layer and protects the steel from corrosion even if the coating is scratched.
18. Which metal is toxic and was commonly used in paints and some old batteries, but must be handled carefully?
Lead is a heavy, toxic metal once used in paints and in lead-acid batteries; handling and disposal require caution because of health risks.
19. Which ferrous metal is often used for heavy-duty grates and jiko (charcoal stove) parts because of strength and heat resistance?
Cast iron is a ferrous material with good compressive strength and heat resistance, making it suitable for stove grates and similar heavy-duty parts.
20. What key difference allows stainless steel to resist rust compared with mild steel?
Chromium in stainless steel reacts with oxygen to form a thin, stable chromium oxide layer that prevents further corrosion of the iron beneath.
21. Which metal develops a green layer called a patina (verdigris) when it corrodes outdoors?
Copper corrodes to form green compounds (patina or verdigris) such as copper carbonate; this is commonly seen on roofs and statues.
22. Which metal is easily and repeatedly recycled without losing its properties and is commonly collected in Kenya for reuse?
Aluminium can be recycled many times with little loss of quality, uses much less energy to reprocess than to produce new aluminium, and is economically valuable to collect.
23. Which non-ferrous metal is valued for ductility and used for making telephone and power lines?
Copper is ductile, has excellent electrical conductivity and is commonly used for power and communication cables.
24. Which metal is commonly used as a sacrificial anode to protect steel (for example in marine fittings or pipelines)?
Zinc corrodes preferentially and is used as a sacrificial anode to protect steel structures from corrosion in marine and other environments.
25. What name is given to the ferrous alloy produced when carbon is added to iron?
Steel is an alloy of iron and carbon (with varying carbon content) and is the principal ferrous alloy used in construction, tools and machinery.