331. For what value of Prandtl number, St = f/2?
1.5
1
> 1
< 1
✅ The correct answer is option B.
Heat Transfer MCQs
332. Dietus-Boelter equation cannot be used for molten metals mainly due to its very low
Prandtl number
Grashoff number
Thermal conductivity
Viscosity
✅ The correct answer is option A.
333. Heat transfer rate per unit area is called
Thermal conductivity
Heat flux
Heat transfer co-efficient
Thermal diffusivity
✅ The correct answer is option B.
334. Steam condensate is recovered by steam traps and recycled for use as boiler feed water, because of its low
Hardness
Dissolved soilds content
Suspended solids content
All of the above
✅ The correct answer is option D.
335. Controlling heat transfer film co-efficient is the one, which offers __________ resistance to heat transfer.
No
The least
The largest
Lower
✅ The correct answer is option C.
336. __________ paint has the maximum absorption coefficient.
Black
Yellow
White
Grey
✅ The correct answer is option A.
337. Maximum heat transfer rate is obtained in __________ flow.
Laminar
Turbulent
Creeping
Transition region
✅ The correct answer is option B.
338. Bulk of the convective heat transfer resistance from a hot tube surface to the fluid flowing in it, is
In the central core of the fluid
Uniformly distributed throughout the fluid
Mainly confined to a thin film of fluid near the surface
None of these
✅ The correct answer is option C.
339. ‘Duhring’s plot’ is of use in
Extractive distillation
Evaporation
Leaching
Absorption
✅ The correct answer is option B.
340. The ratio of momentum diffusivity to thermal diffusivity is the __________ number.
Prandtl
Nusselt
Stanton
Grashoff
✅ The correct answer is option A.