On polished surfaces
On rough surfaces
In the absence of agitation
None of these
✅ The correct answer is option B.
Heat Transfer MCQs
For shell and tube heat exchanger, with increasing heat transfer area, the purchased cost per unit heat transfer area
Increases
Decreases
Remains constant
Passes through a maxima
✅ The correct answer is option D.
Conduction occurs in the buffer zone for a fluid flowing through a heated pipe, only when Prandtl number is
0.1
>1
< 1
L
✅ The correct answer is option A.
__________ heat exchanger is the most suitable, when the temperature of shell side fluid is much higher than that of tube side.
Single pass, fixed tube sheet
U-tube
Three pass, fixed tube sheet
None of these
✅ The correct answer is option B.
Agitated film evaporator is suitable for concentrating __________ liquids.
Foaming
Viscous
Very thin
Corrosive
✅ The correct answer is option B.
Reason for operating an evaporator in multiple effect is to secure
Increased steam economy
Decreased steam consumption
Both A and B
Increased capacity
✅ The correct answer is option C.
One kilogram of water at 0°C is changed to superheated steam of one atm pressure and 300° C. The major heat consumption in the process will be to
Heat the water from 0°C to 100°C
Evaporate the water
To superheat the steam
Data insufficient, can
✅ The correct answer is option B.
A perfect black body is a perfect __________ of radiation.
Absorber
Emitter
Both A & B
Neither A nor B
✅ The correct answer is option C.
At what value of Prandtl number, the hydrodynamic and thermal boundary layers are identical?
0.5
1
1.5
80
✅ The correct answer is option B.
In SI units, fouling factor is expressed in
m²°K/W
W/m²°K
m²°K
m°K/W
✅ The correct answer is option A.