Sparks Academy - MCQ - TNPSC JTO - JTO - 540 - Trade - Workshop Calculation Science 540 Unit 2 Material Science and Heat Treatment

49)

What is the primary technique used in case hardening?

A.

Annealing

B.

Carburizing

C.

Tempering

D.

Quenching

50)

What property of rubber makes it suitable for making tires?

A.

Elasticity

B.

High thermal conductivity

C.

Electrical insulation

D.

Low weight

51)

What is the primary goal of hardening in steel?

A.

To increase tensile strength

B.

To improve ductility

C.

To reduce brittleness

D.

To decrease hardness

52)

Which property makes copper suitable for electrical wiring?

A.

High thermal conductivity

B.

High electrical conductivity

C.

High corrosion resistance

D.

Lightweight

53)

What is the main purpose of the normalizing process?

A.

To refine grain structure

B.

To harden the material

C.

To increase brittleness

D.

To reduce ductility

54)

Which type of cast iron is known for its excellent damping properties?

A.

Grey cast iron

B.

White cast iron

C.

Ductile iron

D.

Malleable iron

55)

Which phase transformation occurs during quenching?

A.

Ferrite to Pearlite

B.

Austenite to Martensite

C.

Cementite to Ferrite

D.

Pearlite to Bainite

56)

Which property is essential for thermal insulating materials?

A.

Low thermal conductivity

B.

High electrical conductivity

C.

High density

D.

High ductility

57)

What property of alloy steel is improved by adding molybdenum?

A.

Strength at high temperatures

B.

Electrical conductivity

C.

Light weight

D.

Ductility

58)

What is the effect of tempering on hardened steel?

A.

Increases brittleness

B.

Reduces hardness but increases toughness

C.

Reduces ductility

D.

Increases grain size

59)

How does vulcanization improve the properties of rubber?

A.

Increases elasticity and strength

B.

Reduces thermal resistance

C.

Increases electrical conductivity

D.

Reduces hardness

60)

What microstructure is formed in steel when cooled slowly below its lower critical temperature?

A.

Ferrite and Pearlite

B.

Austenite

C.

Martensite

D.

Cementite

61)

What is the main benefit of annealing metal?

A.

Increase hardness

B.

Increase ductility

C.

Decrease grain size

D.

Improve thermal conductivity

62)

Which element in alloy steel is responsible for improving its wear resistance?

A.

Chromium

B.

Copper

C.

Zinc

D.

Nickel

63)

What contributes to the elasticity of rubber?

A.

Cross-linking of polymer chains

B.

Presence of sulfur

C.

Low density

D.

High thermal resistance

64)

What is a major disadvantage of high-carbon steel?

A.

Low ductility

B.

High thermal expansion

C.

Poor machinability

D.

Low hardness