Increases
Decreases
Remains unchanged
May increase or decrease ; depending on temperature
✅ The correct answer is option A.
Heat Transfer MCQs
Which of the following is directly concerned with the heat transfer?
Strouhal number
Sherwood number
Euler number
Grashoff number
✅ The correct answer is option D.
Intermittant tube cleaning is possible to be done in case of a __________ evaporator.
Basket type
Horizontal tube
Calendria
None of these
✅ The correct answer is option A.
Heat transfer occurs by natural convection because change in temperature causes difference in
Viscosity
Density
Thermal conductivity
Heat capacity
✅ The correct answer is option B.
Water is normally used as a coolant in the heat exchange equipments mainly because ofits
Abundance & high heat capacity
Low density
Low viscosity
High fluidity
✅ The correct answer is option A.
According to Reynolds analogy, Stanton number is equal to (where, f = Fanning friction factor)
2f
f
f/2
f/4
✅ The correct answer is option C.
Pick out the correct equation.
JH = (St)(Pr)2/3 = f/2
JH = (St)(Pr)1/3 = f/2
JH = (St)2/3(Pr) = f/2
JH = (St)1/3(Pr) = f/2
✅ The correct answer is option A.
A composite flat wall of a furnace is made of two materials ‘A’ and ‘B’. The thermal conductivity of ‘A’ is twice of that of material ‘B’, while the thickness of layer of ‘A’ is half that of B. If the temperature at the two sides of the wall are 400 and 1200°K, then the temperature drop (in °K) across the layer of material ‘A’ is
125
133
150
160
✅ The correct answer is option D.
The Stefan-Boltzman constant depends on the
Medium
Temperature
Surface
None of these
✅ The correct answer is option D.
The purpose of providing a ‘catchall’ in the vapor line of an evaporator is to
Create vacuum
Regulate the vapor flow
Vent the non-condensible gases
Arrest the entrained liquid
✅ The correct answer is option D.