Engineering Materials MCQs

Question 1

For the allotropic forms of iron, the points of arrest are

Accepted Answer

The points of discontinuity

Answer

The points where no further change occurs

Answer

Constant for all metals

Answer

The points where there is no further flow of metal

Question 2

Hematite iron ore contains iron about

Accepted Answer

70%

Answer

30%

Answer

45%

Answer

55%

Question 3

In grey cast iron, carbon is present in the form of

Accepted Answer

Flakes

Answer

Cementite

Answer

Free carbon

Answer

Spheroids

Question 4

In malleable iron, carbon is present in the form of

Accepted Answer

Nodular aggregates of graphite

Answer

Cementite

Answer

Free carbon

Answer

Flakes

Question 5

Nodular iron has

Accepted Answer

All of the above

Answer

High machinability

Answer

Low melting point

Answer

High tensile strength

Question 6

Nickel in steel

Accepted Answer

Gives ductility, toughness, tensile strength and anti-corrosion properties

Answer

Improves wear resistance, cutting ability and toughness

Answer

Refines grain size and produces less tendency to carburisation, improves corrosion and heat resistant properties

Answer

Improves cutting ability and reduces hardenability

Question 7

Dislocations in materials refer to the following type of defect

Accepted Answer

Line defect

Answer

Point defect

Answer

Plane defect

Answer

Volumetric defect

Question 8

The main alloying elements high speed steel in order of increasing proportion are

Accepted Answer

Vanadium, chromium, tungsten

Answer

Tungsten, titanium, vanadium

Answer

Chromium, titanium, vanadium

Answer

Tungsten, chromium, titanium

Question 9

Induction hardening is basically a

Accepted Answer

Surface hardening process

Answer

Carburising process

Answer

Core hardening process

Answer

None of these