Chemical Engineering - Chemical Engineering Basics

21. 

Powder metallurgy process does not make metal powder by

A. atomisation
B. grinding/milling
C. hammering
D. electrolytic deposition

Answer: Option C

Explanation:

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22. 

In the blast furnace, incorporation of water vapour in the blast gives the following effect.

A. Increases the reducing potential of the gas.
B. Increases the flame temperature.
C. No significant change occurs.
D. Increases the hydrogen content in the metal.

Answer: Option A

Explanation:

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23. 

Pick out the wrong statement.

A. A ferromagnetic material becomes paramagnetic above the 'Curie temperature'.
B. Permanent magnets are made of hard materials, whereas electromagnets require soft magnetic materials.
C. Soft magnetic materials (e.g., pure iron) have higher permeability and low hysterisis loss and coercive forces.
D. Tungsten steel and alnico are not hard magnetic materials.

Answer: Option D

Explanation:

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24. 

The usual energy consumption in electric arc furnace steel making is __________ KWh/ton of steel.

A. 60 - 100
B. 400 - 700
C. 1200 -1500
D. 2000 - 2300

Answer: Option B

Explanation:

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25. 

Maximum permissible air velocity in pipelines is about __________ metre/second.

A. 5
B. 10
C. 20
D. 40

Answer: Option B

Explanation:

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