MATERIAL SCIENCE MCQ SET 1
Q1. The crystal structure in which atoms are located at the corners of a cube only is called:
A) Body-centered cubic (BCC)
B) Face-centered cubic (FCC)
C) Simple cubic (SC)
D) Hexagonal close-packed (HCP)
Answer: C) Simple cubic (SC)
Explanation: In SC structure, atoms occupy only the cube corners. Coordination number = 6.
Q2. The most ductile metallic crystal structure is:
A) BCC
B) FCC
C) HCP
D) SC
Answer: B) FCC
Explanation: FCC metals (e.g., Al, Cu) have the highest number of slip systems, making them most ductile.
Q3. Which of the following is a ferrous alloy?
A) Brass
B) Bronze
C) Steel
D) Aluminum alloy
Answer: C) Steel
Explanation: Steel is an alloy of iron and carbon; ferrous alloys contain iron as the main component.
Q4. The ability of a material to resist plastic deformation is called:
A) Ductility
B) Toughness
C) Hardness
D) Elasticity
Answer: C) Hardness
Explanation: Hardness measures resistance to localized plastic deformation or indentation.
Q5. Which heat treatment process is used to increase hardness of steel?
A) Annealing
B) Quenching
C) Normalizing
D) Tempering
Answer: B) Quenching
Explanation: Quenching involves rapid cooling, producing hard martensitic structure.
Q6. The main strengthening mechanism in cold working is:
A) Grain boundary strengthening
B) Strain hardening
C) Solid solution strengthening
D) Precipitation hardening
Answer: B) Strain hardening
Explanation: Plastic deformation increases dislocation density, strengthening the metal.
Q7. Stainless steel contains a minimum of:
A) 8% Chromium
B) 12% Nickel
C) 5% Carbon
D) 2% Copper
ย Answer: A) 8% Chromium
Explanation: Chromium forms a passive oxide layer, giving corrosion resistance.
Q8. Which of the following is a non-ferrous alloy?
A) Cast iron
B) Bronze
C) Carbon steel
D) Tool steel
Answer: B) Bronze
Explanation: Bronze is an alloy of copper and tin; non-ferrous alloys do not contain iron.
Q9. The property of a material to absorb energy before fracture is called:
A) Toughness
B) Hardness
C) Ductility
D) Elasticity
Answer: A) Toughness
Explanation: Toughness combines strength and ductility, measured by impact tests.
Q10. Martensite is formed in steel by:
A) Slow cooling from austenite
B) Rapid quenching from austenite
C) Heating below critical temperature
D) Cold working
Answer: B) Rapid quenching from austenite
Explanation: Martensite is a supersaturated, hard, and brittle phase formed by rapid cooling.
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