Chemical Engineering Basics

Question: A machine having assumed life of 20 years is purchased for Rs 32000/-. Its scrap value at the end of its life is Rs 8000/-. If the depreciation is calculated by diminishing balance method, then percentage reduction in its value at the end of first year is __________ percent.
[A].

6.7

[B].

7.6

[C].

10.3

[D].

15.2

Answer: Option A

Explanation:

No answer description available for this question.

Question: During sensible cooling of air, its wet bulb temperature
[A].

decreases but dew point remains constant.

[B].

increases but dew point remains constant.

[C].

increases & the dew point decreases.

[D].

decreases & the dew point increases.

Answer: Option B

Explanation:

No answer description available for this question.

Question: A freely floating object is stable, if its centre of buoyancy
[A].

coincides with its centre of gravity.

[B].

lies below its centre of gravity.

[C].

lies below its metacentre.

[D].

none of these.

Answer: Option A

Explanation:

No answer description available for this question.

Question: Compressed dry air is used as the cutting fluid, while machining
[A].

steel

[B].

cast iron

[C].

aluminium

[D].

none of these

Answer: Option B

Explanation:

No answer description available for this question.

Question: As the fluid flow rate increases, the float of the rotameter
[A].

rises in the tube.

[B].

rotates at higher speed.

[C].

rotates at lower speed.

[D].

drops down in the tube.

Answer: Option A

Explanation:

No answer description available for this question.

Question: In case of condensers & evaporators operating under given terminal conditions, LMTD (logarithmic mean temperature difference) for counter flow as compared to that for parallel flow is
[A].

more

[B].

less

[C].

equal

[D].

much more

Answer: Option C

Explanation:

No answer description available for this question.

Question: According to maximum shear stress failure criterion, yielding in material occurs, when the maximum shear stress is equal to __________ times the yield stress.
[A].

0.5

[B].

2

[C].

2

[D].

3/2

Answer: Option A

Explanation:

No answer description available for this question.

Question: With increase in __________ Knocking tendency in a spark ignition petrol engine decreases.
[A].

supercharging

[B].

wall temperature

[C].

compression ratio

[D].

engine speed

Answer: Option D

Explanation:

No answer description available for this question.

Question: For the same heat input & compression ratio, efficiency of Otto cycle is higher than that of diesel cycle, because in Otto cycle.
[A].

heat rejection is lower.

[B].

expansion & compression are isentropic.

[C].

maximum temperature is higher.

[D].

combustion is at constant volume.

Answer: Option A

Explanation:

No answer description available for this question.

Question: Expansion device used in a window air-conditioner is a/an
[A].

automatic expansion valve.

[B].

thermostatic expansion valve.

[C].

float valve.

[D].

capillary tube.

Answer: Option D

Explanation:

No answer description available for this question.