CHEMICAL ENGINEERING

Question: __________ welding will be the most suitable for butt welding two 20 cms thick boiler drum mild steel plates.
[A].

Electrical resistance

[B].

Electroslag

[C].

Plasma torch

[D].

Submerged arc

Answer: Option B

Explanation:

No answer description available for this question.

Question: Current employed in resistance welding ranges from __________ kVA/cm2 .
[A].

1.2 to 2.5

[B].

4.5 to 6.2

[C].

7.5 to 8.5

[D].

10.5 to 15.5

Answer: Option B

Explanation:

No answer description available for this question.

Question: Deformation band is absent in materials having __________ lattice crystal structure.
[A].

fcc

[B].

bcc

[C].

hcp

[D].

none of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: Ingrannular corrosion occurs __________ stainless steel.
[A].

in all types of steels except

[B].

at the surface of

[C].

along grain boundaries of

[D].

in the core of

Answer: Option C

Explanation:

No answer description available for this question.

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.