Chemical Engineering Basics MCQs

Question 1

Which of the following pairs regarding the effect of alloying elements in steels are not matched correctly?

Accepted Answer

Cobalt: It contributes to rerl hardness by hardening ferrite

Answer

Molybdenum: It forms abrasion resisting particles

Answer

Phosphorous: It improves machinability in free cutting steels

Answer

Silicon: It reduces oxidation resistance

Question 2

Corrosion of metals can not be prevented by its

Accepted Answer

Tempering

Answer

Chromising

Answer

Aluminising

Answer

Alloying

Question 3

Which of the following materials has the least scrap value?

Accepted Answer

Stainless steel

Answer

Aluminium

Answer

Brass

Answer

Copper

Question 4

A semi-conductor is damaged & behaves like a conductor, on passing a strong electric current through it, because it heats up the crystals & breaks the covalant bonds resulting in __________ electrons.

Accepted Answer

Excess of

Answer

Lack of free

Answer

Decrease in

Answer

None of these

Question 5

Inertial forces are obtained, when the elastic forces are multiplied by __________ number.

Accepted Answer

Mach

Answer

Froude

Answer

Reynolds

Answer

Euler

Question 6

Lubricants can be used to

Accepted Answer

All of the above

Answer

Transmit power hydraulically

Answer

Form a seal in compressors

Answer

Remove contaminants by flushing and to insulate transformers, switchgears etc

Question 7

Lubrication is done to control

Accepted Answer

All of the above

Answer

Friction

Answer

Wear

Answer

Temperature

Question 8

In case of compression of one kg of air, the work done will be the least, when the value of polytropic index 'n' is

Accepted Answer

1

Answer

1.4

Answer

1.5

Answer

$$\gamma = \frac{{{{	ext{C}}_{	ext{p}}}}}{{{{	ext{C}}_{	ext{v}}}}}$$

Question 9

Large diameter reinforced cement concrete (RCC) pipes are generally joined by __________ joint.

Accepted Answer

Collar

Answer

Flanged iron

Answer

Flexible

Answer

Expansion