Chemical Engineering Basics

Question: In BOF, desiliconisation is a first order reaction. So the silicon content of the metal decreases
[A].

linearly with time.

[B].

exponentially with time.

[C].

logarithmically with time.

[D].

in proportion to the square root of time.

Answer: Option A

Explanation:

No answer description available for this question.

Question: With increase in annealing temperature, the following defect density decreases.
[A].

Vacancy

[B].

Dislocation

[C].

Grain boundary

[D].

All of them

Answer: Option D

Explanation:

No answer description available for this question.

Question: Dislocation cross-slip is difficult in those materials, which have
[A].

large number of slip systems.

[B].

high work hardening rate.

[C].

coarse grain size.

[D].

low stacking fault energy.

Answer: Option D

Explanation:

No answer description available for this question.

Question: Malleabilisation heat treatment is performed on
[A].

cast steel

[B].

grey cast iron

[C].

white cast iron

[D].

spheroidal graphite cast iron

Answer: Option C

Explanation:

No answer description available for this question.

Question: Identify the correct statement with reference to the extractive metallurgy of aluminium.
[A].

The electrolyte consists of molten Na3AlF6 with approximately 1 to 8% Al2O3.

[B].

Approximately 80% of the aluminium deposited on the cathode comes from cryolite.

[C].

Sodium is deposited along with aluminium, but is immediately vaporised.

[D].

Anode effect sets in when the cryolite concentration goes below 40%.

Answer: Option A

Explanation:

No answer description available for this question.

Question: Identify the correct statement.
[A].

Sphlerite is zinc oxide.

[B].

The first law of the thermodynamics is stated as δE = δQ – δW.

[C].

Lead can be produced in a blast furnace.

[D].

T. ferrooxidans is a fungus that can be used for leaching chalcopyrite.

Answer: Option C

Explanation:

No answer description available for this question.

Question: Draft allowance given to patterns is for
[A].

compensating the liquid state shrinkage.

[B].

easy removal of pattern from the mold cavity.

[C].

providing support for the core placement.

[D].

compensating the solidification shrinkage.

Answer: Option B

Explanation:

No answer description available for this question.

Question: Identify the false statement
[A].

Martensitic steels are less susceptible to pitting corrosion than austenitic steels.

[B].

Pitting corrosion is usually very localised.

[C].

Hydrogen embrittlement is facilitated by tensile stress.

[D].

Stress corrosion cracking is facilitated by tensile stress.

Answer: Option A

Explanation:

No answer description available for this question.

Question: Blast furnace is a
[A].

counter current reactor

[B].

co-current reactor

[C].

cross-current reactor

[D].

combination of all the three

Answer: Option A

Explanation:

No answer description available for this question.

Question: During decarburising of a plain carbon steel, the thickness of ferrite layer growth is proportional to
[A].

time

[B].

square root of time

[C].

square of time

[D].

cube of time

Answer: Option B

Explanation:

No answer description available for this question.