Chemical Engineering Basics

Question: Maximum permissible air velocity in pipelines is about __________ metre/second.
[A].

5

[B].

10

[C].

20

[D].

40

Answer: Option B

Explanation:

No answer description available for this question.

Question: Electrometallurgy is not involved in the extraction of __________ from its ore.
[A].

aluminium

[B].

tin

[C].

lead

[D].

both(b) & (c)

Answer: Option D

Explanation:

No answer description available for this question.

Question: Even minute presence of impurities in copper impairs its electrical conductivity seriously. Electrolytic refinning of blister copper is resorted to, when
[A].

cheap electricity is available.

[B].

the precious metal content of copper is high.

[C].

there is a demand for ultrapure (99.99%) electrolytic copper.

[D].

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

Answer: Option D

Explanation:

No answer description available for this question.

Question: Electrolytic reduction cell used for conversion of calcined Al2O3 to Al is a carbon lined furnace operating at 800-900 °C. The purpose of electric current supplied to the furnace is to
[A].

achieve very high purity of aluminium (99.9%).

[B].

keep the electrolyte in liquid condition by the generation of heat.

[C].

electrolytically dissociate alumina.

[D].

both(b) & (c).

Answer: Option D

Explanation:

No answer description available for this question.

Question: Electrometallurgical methods of metal extraction is normally used for those metals
[A].

whose oxide/ore is not reduced by carbon.

[B].

which fall in the category of alkali & alkaline earth metals.

[C].

which stands higher in the electrochemical series of the metal.

[D].

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

Answer: Option D

Explanation:

No answer description available for this question.

Question: Galvanic corrosion
[A].

occurs in a bimetal couple.

[B].

occurs in highly stressed metallic parts only.

[C].

is exemplified by caustic embrittlement of boiler tubes.

[D].

is also called dezincification.

Answer: Option A

Explanation:

No answer description available for this question.

Question: Coating thickness in case of galvanising of steel sheet generally corresponds to the deposition of __________ gms of zinc per m2 of steel strip.
[A].

5-10

[B].

1000-1500

[C].

120-500

[D].

1500-3000

Answer: Option C

Explanation:

No answer description available for this question.

Question: Factor of safety is the ratio of the __________ stress to the working stress.
[A].

tensile

[B].

compressive

[C].

yield

[D].

bearing

Answer: Option C

Explanation:

No answer description available for this question.

Question: Half life of a radioactive isotope corresponds to the time required for half of the __________ to decay.
[A].

atoms

[B].

neutrons

[C].

nucleons

[D].

electrons

Answer: Option A

Explanation:

No answer description available for this question.

Question: An ideal material for making cooking vessels should have
[A].

high heat capacity.

[B].

low heat capacity.

[C].

high thermal conductivity.

[D].

both (b) and (c).

Answer: Option D

Explanation:

No answer description available for this question.