Total condenser
Vacuum evaporator
Partial condenser
Double pipe heat exchanger
✅ The correct answer is option C.
Heat Transfer MCQs
Water always boils when its
Temperature reaches 100° C
Vapour pressure equals 76 cm of Hg
Saturated vapour pressure equals the external pressure on its surface
Saturated vapour pressure is less than the atmospheric pressure
✅ The correct answer is option C.
Vibrations in the tubes of a shell and tube heat exchanger is induced due to the
Flow of fluid on the tube and shell sides
Oscillations in the flow of shell/tube sides fluid
Vibrations transmitted through piping and/or supports due to external reasons
All of the above
✅ The correct answer is option D.
The energy radiated from a surface Q at absolute temperature T is related as
Q ∝ T²
Q ∝ T⁴
Q ∝ T³
None of these
✅ The correct answer is option B.
All analogy equations connecting friction factor and heat transfer co-efficient apply only to
Wall or skin friction
Form friction
Both A and B
Turbulent flow
✅ The correct answer is option A.
Which one gives the monochromatic emissive power for black body radiation?
Planck’s law
Kirchhoffs law
Wien’s law
Stefan-Boltzman law
✅ The correct answer is option A.
A long iron rod initially at a temperature of 20°C has one end dipped in boiling water (100°C) at time, t = 0. The curved surface of the rod is insulated so that heat conduction is one dimensional in the axial direction. The temperature at a distance 100 mm from the dipped end becomes 40°C at time, t = 200 s. The same temperature is achieved at a distance of 200 mm from the dipped end at time
t = 283 s
t = 356 s
t = 400 s
t = 800 s
✅ The correct answer is option D.
Evaporator tubes are generally
Horizontal
Vertical
Inclined
Random
✅ The correct answer is option B.
jH factor for heat transfer depends upon the __________ number.
Biot
Nusselt
Reynolds
Prandtl
✅ The correct answer is option C.
The absorptivity of a grey body at a given temperature __________ with increasing wavelength of radiation.
Increases
Decreases
Remains constant
May increase or decrease ; depends on the material
✅ The correct answer is option D.