Oily
Coated
Clean & smooth
Dirty
✅ The correct answer is option C.
Heat Transfer MCQs
Removal of __________ heat is involved in the condensation of a vapor under saturated conditions.
Super
Sensible
Latent
Both B & C
✅ The correct answer is option B.
The statement that “maximum wavelength of radiation is inversly proportional to the temperature” is __________ law.
Stefan-Boltzman’s
Planck’s
Wien’s displacement
None of these
✅ The correct answer is option C.
Which type of heat exchanger is preferred for heavy heat loads?
Double pipe
Plate fine
Series and parallel set of shell and tube
None of these
✅ The correct answer is option C.
For flow over a flat plate, the ratio of thermal boundary layer thickness, ‘xt’ and hydrodynamic boundary layer thickness ‘x’ is equal to (where, NPr = Prandtl number)
NPr
NPr1/3
NPr-1
NPr-1/3
✅ The correct answer is option B.
Heat transfer efficiency leading of energy conservation in a heat exchanger can be achieved by
Keeping the heat transfer surface clean
Enhancing the fluid pumping rate
Increasing the tube length
None of these
✅ The correct answer is option A.
With increase in temperature, the thermal conductivity of most liquids
Increases
Decreases
Remains same
First increases upto a certain temperature and then becomes constant
✅ The correct answer is option B.
A concentric double pipe heat exchanger as compared to the shell and tube heat exchanger for the same heat load requires
Less heating surface
More space
Lower maintenance cost
None of these
✅ The correct answer is option B.
Heat flux through several resistances in series in analogous to the current flowing through several
Resistances in parallel
Capacitors in series
Resistances in series
None of these
✅ The correct answer is option C.
A body is called grey if the monochromatic emissivity of the body is
Zero
Unity
Same for all wavelengths
Different for all wavelengths
✅ The correct answer is option C.