Heat Transfer MCQs

Question 1

Among liquids, water has a comparatively high value of thermal conductivity, due to its

Accepted Answer

Partial ionisation

Answer

Low density

Answer

High viscosity

Answer

Dense structure

Question 2

Evaporation by thermocompression results in the

Accepted Answer

Both A and B

Answer

Saving of steam

Answer

Realisation of multiple effect economy in a single effect

Answer

None of these

Question 3

Which of the following is directly concerned with the heat transfer?

Accepted Answer

Grashoff number

Answer

Strouhal number

Answer

Sherwood number

Answer

Euler number

Question 4

Evaporator tubes are generally

Accepted Answer

Vertical

Answer

Horizontal

Answer

Inclined

Answer

Random

Question 5

Boiling of milk in an open vessel is an example of __________ boiling.

Accepted Answer

Film

Answer

Sub-cooled

Answer

Saturated nucleate

Answer

None of these

Question 6

The actual temperature drop across the heating surface of an evaporator depends on the

Accepted Answer

All of the above

Answer

Liquid depth over the heating surface

Answer

Solution being evaporated

Answer

Pressure difference between the steam chest and the vapor space above the boiling liquid

Question 7

In Biot number, the characteristic length used is the ratio of the __________ of the solid.

Accepted Answer

Volume to surface area

Answer

Perimeter to surface area

Answer

Surface area to volume

Answer

Surface area to perimeter

Question 8

Steam consumption in kg/hr in case of an evaporator is given by (where, C & E are capacity the economy of the evaporator respectively)

Accepted Answer

$$\frac{{	ext{C}}}{{	ext{E}}}$$

Answer

$$\frac{{	ext{E}}}{{	ext{C}}}$$

Answer

CE

Answer

$$\frac{1}{{{	ext{CE}}}}$$

Question 9

Steam condensate is recovered by steam traps and recycled for use as boiler feed water, because of its low

Accepted Answer

All of the above

Answer

Hardness

Answer

Dissolved soilds content

Answer

Suspended solids content