Question

Which of the following alloys are correctly matched with their uses? \[ \text{i) Li/Mg} \quad \text{armour plates} \] \[ \text{ii) Cu/Be} \quad \text{high strength springs} \] \[ \text{iii) Mg/Al} \quad \text{aircraft construction} \]

• A. i, ii only
• B. ii, iii only
• C. i, iii only
• D. i, ii, iii

Hint:

When studying alloys, remember their key properties like strength, lightness, and corrosion resistance to match them with their uses.

Answer 1

The Correct Option is D

Let's check the uses of each alloy:
- Li/Mg: Lithium and magnesium alloys are widely used in making armour plates, hence option (i) is correct.
- Cu/Be: Copper and beryllium alloys are known for their high strength, particularly in springs, so option (ii) is correct.
- Mg/Al: Magnesium and aluminium alloys are commonly used in the aerospace industry, especially in aircraft construction, making option (iii) correct.
Thus, all the alloys are correctly matched with their uses.
The correct answer is option (4) i, ii, iii.

Answer 2

Step 1: Understand the uses of Li/Mg alloys.
- Lithium (Li) and Magnesium (Mg) alloys are lightweight and have good mechanical strength.
- These properties make them ideal for making armour plates that require both strength and reduced weight.
- Hence, Li/Mg alloys are used in armour plating applications.

Step 2: Understand the uses of Cu/Be alloys.
- Copper (Cu) and Beryllium (Be) alloys are known for their excellent strength and elasticity.
- Due to these properties, they are commonly used to manufacture high-strength springs and other components that need to withstand repeated stress.
- Therefore, Cu/Be alloys are used in spring manufacturing.

Step 3: Understand the uses of Mg/Al alloys.
- Magnesium (Mg) and Aluminium (Al) alloys combine light weight with high strength.
- These qualities make them suitable for aerospace applications, especially in aircraft construction where reducing weight without compromising strength is crucial.
- Thus, Mg/Al alloys are widely used in the aerospace industry.

Step 4: Conclusion.
All the alloys are correctly matched with their respective uses:
- (i) Li/Mg for armour plates,
- (ii) Cu/Be for springs,
- (iii) Mg/Al for aerospace.
Hence, the correct answer is option (4) i, ii, iii.