Materials and Construction

Question: __________ iron is produced, when molten pig iron is chilled suddenly.
[A].

White cast

[B].

Grey cast

[C].

Wrought

[D].

none of these

Answer: Option A

Explanation:

No answer description available for this question.

Question: Corrosion involves exchange of electrons in __________ corrosion.
[A].

chemical

[B].

electrochemical

[C].

both (a) & (b)

[D].

neither (a) nor (b)

Answer: Option C

Explanation:

No answer description available for this question.

Question: Iron rust is
[A].

ferrous oxide.

[B].

hydrated ferric oxide.

[C].

powdered iron.

[D].

ferric sulphide.

Answer: Option B

Explanation:

No answer description available for this question.

Question: Carbon is present in steel wholly in the
[A].

combined form.

[B].

free state as graphite.

[C].

both (a) and (b).

[D].

neither (a) nor (b).

Answer: Option A

Explanation:

No answer description available for this question.

Question: With increase in carbide/graphite ratio in cast iron, its
[A].

hardness & brittleness increases.

[B].

ductility decreases.

[C].

both (a) and (b).

[D].

neither (a) nor (b).

Answer: Option C

Explanation:

No answer description available for this question.

Question: Metalloid is
[A].

highly electronegative in nature.

[B].

an element which exhibits the properties of both metal & non-metal.

[C].

an alloy.

[D].

all (a), (b) and (c).

Answer: Option B

Explanation:

No answer description available for this question.

Question: Nitriding of steel is done (in electric furnace) at __________ °C.
[A].

510

[B].

1720

[C].

2210

[D].

910

Answer: Option A

Explanation:

No answer description available for this question.

Question: Carbon percentage is the same in cast iron and
[A].

wrought iron

[B].

pig iron

[C].

mild steel

[D].

high silicon (14%) iron

Answer: Option B

Explanation:

No answer description available for this question.

Question: Beehive coke ovens are made of __________ bricks.
[A].

silica

[B].

fireclay

[C].

silicon carbide

[D].

corundum

Answer: Option A

Explanation:

No answer description available for this question.

Question: Ceramic recuperators are generally made of
[A].

silicon carbide.

[B].

calcium carbide.

[C].

fireclay bricks.

[D].

high alumina bricks.

Answer: Option A

Explanation:

No answer description available for this question.