CHEMICAL ENGINEERING

Question: As per international norms, the maximum permissible value of noise level in the industrial environment is __________ decibels as measured at a distance of 1.5 metres from the source of noise.
[A].

110

[B].

85

[C].

60

[D].

45

Answer: Option B

Explanation:

No answer description available for this question.

Question: A solar cell converts the sunlight directly into __________ energy.
[A].

thermal

[B].

electrical

[C].

mechanical

[D].

chemical

Answer: Option B

Explanation:

No answer description available for this question.

Question: If the head is doubled in & centrifugal pump, the power required will increase in the ratio of
[A].

23

[B].

23/2

[C].

25/2

[D].

21/3

Answer: Option B

Explanation:

No answer description available for this question.

Question: __________ is the process of coating the surface of steel with aluminium oxide, thereby imparting it increased resistance to corrosion & oxidation upto a temperature of 700°C.
[A].

Vaneering

[B].

Galvanising

[C].

Electroplating

[D].

Calorising

Answer: Option D

Explanation:

No answer description available for this question.

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.