Material Science MCQ Set 8

MATERIAL SCIENCE MCQ SET 8

Q1. The unit cell with atoms at corners and centers of all faces is called:

A) Simple cubic
B) BCC
C) FCC
D) HCP

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Answer: C) FCC
Explanation: Face-centered cubic (FCC) structure has high packing efficiency and ductility.

Q2. Martensitic steel is:

A) Soft and ductile
B) Hard and brittle
C) Tough and ductile
D) Low strength

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Answer: B) Hard and brittle
Explanation: Martensite forms via rapid quenching and is supersaturated carbon steel phase.

Q3. The main constituent of white cast iron is:

A) Graphite
B) Cementite
C) Ferrite
D) Austenite

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Answer: B) Cementite
Explanation: White cast iron contains iron carbide (cementite), making it hard and brittle.

Q4. Which of the following metals has high corrosion resistance in marine environments?

A) Iron
B) Aluminum
C) Copper-nickel alloy
D) Mild steel

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Answer: C) Copper-nickel alloy
Explanation: Copper-nickel alloys resist seawater corrosion and biofouling.

Q5. Which of the following polymers is thermosetting?

A) Polyethylene
B) PVC
C) Bakelite
D) Nylon

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Answer: C) Bakelite
Explanation: Bakelite forms irreversible chemical bonds on heating, making it a thermoset.

Q6. The process of heating steel below critical temperature to increase ductility is called:

A) Annealing
B) Normalizing
C) Tempering
D) Quenching

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Answer: C) Tempering
Explanation: Tempering reduces brittleness and relieves stresses after quenching.

Q7. Which property is high in ceramics?

A) Ductility
B) Hardness
C) Toughness
D) Electrical conductivity

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Answer: B) Hardness
Explanation: Ceramics are hard due to strong ionic/covalent bonds but are brittle.

Q8. The metal used for making fusible alloys is:

A) Lead
B) Aluminum
C) Copper
D) Iron

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Answer: A) Lead
Explanation: Lead-based fusible alloys have low melting points and are used for safety devices.

Q9. The microstructure of pearlite is:

A) Lamellar mixture of ferrite and cementite
B) Martensite
C) Bainite
D) Austenite

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Answer: A) Lamellar mixture of ferrite and cementite
Explanation: Pearlite gives steel a balance of strength and ductility.

Q10. Which of the following increases toughness?

A) Martensite
B) Bainite
C) Tempered martensite
D) Cementite

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Answer: C) Tempered martensite
Explanation: Tempering reduces brittleness of martensite while retaining hardness.