Cummulatively increases
Cummulatively decreases
Remains constant
And the surface conductance increase
✅ The correct answer is option A.
Heat Transfer MCQs
The range of electromagnetic spectrum important in heat transfer by radiation is __________ microns.
0.38-0.78
0.5-50
100-1000
May-50
✅ The correct answer is option B.
The Graetz number is concerned with the
Mass transfer between a gas and a liquid
Absorption with chemical reaction
Heat transfer in turbulent flow
Heat transfer in laminar flow
✅ The correct answer is option D.
In SI units, thermal conductivity is expressed in
Watt/m.°K
Watt/m². °K
Watt/m². °K
Watt/m4. °K
✅ The correct answer is option A.
The non-dimensional temperature gradient in a liquid at the wall of a pipe is the
Heat flux
Nusselt number
Prandtl number
Schmidt number
✅ The correct answer is option A.
Mode of heat transfer involved in the cooling of air cooled internal combustion engine is
Conduction
Natural convection
Forced convection
None of these
✅ The correct answer is option B.
Baffles in the shell side of a shell and tube heat exchanger
Increase the cross-section of the shell side liquid
Force the liquid to flow parallel to the bank
Increase the shell side heat transfer co-efficient
Decrease the shell side heat transfer co-efficient
✅ The correct answer is option C.
Sensible heat absorbed by 1 lb of water when it is heated from 32 to 212°F may be around __________ BTU.
180
970
3.97
Data insufficient, can
✅ The correct answer is option A.
For a laminar flow of fluid in a circular tube, ‘h₁’ is the convective heat transfer co-efficient at velocity ‘V₁’. If the velocity is reduced by half and assuming the fluid properties are constant, the new convective heat transfer co-efficient is
1.26 h₁
0.794 h₁
0.574 h₁
1.741 h₁
✅ The correct answer is option B.
Resistance to heat flow by conduction is proportional to (where, t & ρ are thickness & density of the material respectively and A = area normal to the direction of heat flow. )
T
1/ρ
1/A
All of the above
✅ The correct answer is option D.