Chemical Engineering Basics

Question: Galvanic corrosion can not be prevented by
[A].

cathodic protection.

[B].

anodic protection.

[C].

usage of largest possible anodic area.

[D].

any one of these.

Answer: Option B

Explanation:

No answer description available for this question.

Question: While the recrystallisation temperature for pure metals is 0.3 Tm, the same for alloys is equal to __________ x Tm (where, Tm Melting temperature).
[A].

0.25

[B].

0.45

[C].

0.70

[D].

0.95

Answer: Option C

Explanation:

No answer description available for this question.

Question: The Al2 O3 content of cryolite in Hall-Heroult’s cell is maintained between __________ percent.
[A].

2-5

[B].

18-20

[C].

12-15

[D].

6-12

Answer: Option A

Explanation:

No answer description available for this question.

Question: Maraging steels derive their strength from the following mechanism:
[A].

A fine, highly dislocated and strong martensite.

[B].

Fine dispersions of intermetallics of Fe, Ni, Ti etc.

[C].

Fine dispersions of alloy carbides in a ferrite matrix.

[D].

Fine dispersions of Fe3 C nucleated on dislocations in austenite.

Answer: Option A

Explanation:

No answer description available for this question.

Question: In continuous casting of liquid steel, the mould is made of
[A].

water cooled steel

[B].

water cooled copper.

[C].

refractory oxide.

[D].

silicon carbide.

Answer: Option B

Explanation:

No answer description available for this question.

Question: For efficient performance of a blast furnace, the extent of reduction of Wustite (FeO) should be
[A].

100% indirect reduction.

[B].

100% direct reduction.

[C].

50-60% indirect reduction.

[D].

30-40% indirect reduction.

Answer: Option C

Explanation:

No answer description available for this question.

Question: In the acid Bessemer process, the hot metal should have the following com-positon.
[A].

S < 0.05% and P < 0.05%.

[B].

S < 0.05% and P < 1.5%.

[C].

S < 0.05% and P > 1.5%.

[D].

S > 1.5% and P < 0.05%.

Answer: Option A

Explanation:

No answer description available for this question.

Question: Brazing filler metal used for joining steel plates
[A].

melts below the melting points of base metals.

[B].

melts below 300°C.

[C].

is copper phosphorous alloy.

[D].

is copper.

Answer: Option A

Explanation:

No answer description available for this question.

Question: Cold cracking in the heat affected zone of a high strength steel weld can take place because of the
[A].

retained austenite.

[B].

martensite formation.

[C].

relatively high sulphur content in the base metal.

[D].

sufficient hydrogen present in the welding arc.

Answer: Option B

Explanation:

No answer description available for this question.

Question: Internal cracks in drawn bars are due to
[A].

secondary tensile stresses.

[B].

temperature gradient in the work piece.

[C].

heated dies and grips.

[D].

internal compressive residual stress.

Answer: Option A

Explanation:

No answer description available for this question.