Material Science And Metallurgy (3131904) MCQs

MCQs of Allotropy of Iron, Iron-Iron-Carbide equilibrium system

Showing 31 to 40 out of 79 Questions
31.

Iron-carbon alloys containing 1.7 to 4.3% carbon are known as

(a)

eutectic cast irons

(b)

hypo-eutectic cast irons

(c)

hyper-eutectic cast irons

(d)

none of these

Answer:

Option (b)

32.

The lower critical point for all steels is

(a)

600°C

(b)

700°C

(c)

723°C

(d)

913°C

Answer:

Option (c)

33.

Steel containing 0.8 to 1.5% carbon, is known as

(a)

mild steel

(b)

dead mild steel

(c)

medium carbon steel

(d)

high carbon steel

Answer:

Option (d)

34.

Steel containing upto 0.15% carbon, is known as

(a)

mild steel

(b)

dead mild steel

(c)

medium carbon steel

(d)

high carbon steel

Answer:

Option (b)

35.

An eutectoid steel consists of

(a)

wholly pearlite

(b)

wholly austenite

(c)

pearlite and ferrite

(d)

pearlite and cementite

Answer:

Option (a)

36.

The hardness of steel depends upon the

(a)

amount of cementite it contains

(b)

amount of carbon it contains

(c)

contents of alloying elements

(d)

method of manufacture of steel

Answer:

Option (a)

37.

Nickel when added to copper improves

(a)

machinability

(b)

hardness

(c)

hardness and strength

(d)

strength and ductility

Answer:

Option (b)

38.

The addition of which of the following improves machining of copper?

(a)

Sulphur

(b)

Vanadium

(c)

Tin

(d)

Zinc

Answer:

Option (a)

39.

Silicon when added to copper improves

(a)

machinability

(b)

hardness

(c)

hardness and strength

(d)

strength and ductility

Answer:

Option (c)

40.

Shock resistance of steel is increased by adding

(a)

nickel

(b)

chromium

(c)

nickel and chromium

(d)

sulphur, lead and phosphorus

Answer:

Option (c)

Showing 31 to 40 out of 79 Questions