Related Questions

The scales form in heat exchanges after a period of operation and provide additional resistance to heat transfer with some heat transfer coefficient . The reciprocal of this scale heat transfer coefficient is called .
A scaling factor
B forming factor
C resisting factor
D fouling factor
Extended heat transfer surface like fins are used to increase the heat transfer rate. Fin efficiency is defined as the ratio of heat transferred across the fin surface to the theoretical heat transfer across an equal area held at the
A Surrounding temperature
B Average temperature of the fin
C Temperature of the fin end
D Constant temperature equal to that of the base
Air is to be heated by condensing steam. Two heat exchangers are available (i) a shell and tube heat exchanger and (ii) a finned tube heat exchanger. Tube side heat transfer area are equal in both the cases. The recommended arrangement is
A Finned tube heat exchanger with air inside and steam outside
B Finned tube heat exchanger with air outside and steam inside
C Shell and tube heat exchanger with air inside tubes and steam on shell side
D Shell and tube heat exchanger with air on shell side and steam inside tubes
For shell and tube heat exchanger, with increasing heat transfer area, the purchased cost per unit heat transfer area
A Increases
B Decreases
C Remains constant
D Passes through a maxima
How are the efficiencies of any heat engine (miu) and reversible heat engine (miuR) compared, when both are operating between same heat source and same heat sink?
A miu = miuR
B miu>miuR
C miu
D none of these
According to the film theory of mass transfer, the mass transfer co-efficient is proportional to (where, D = molecular diffusivity)
A D
B D2
C D0.5
D $$\frac{1}{{\text{D}}}$$
Overall mass transfer co-efficient in case of absorption of __________ in water is based on the gas film co-efficient only, as the mass transfer process is gas film (phase) controlling.
A CO2
B SO2
C NH3
D None of these
For experimental determination of mass transfer co-efficient by wetted wall tower, the mass transfer area is
A Calculated
B Unknown
C Known
D Not required
The ratio of the actual mass of water vapour in a unit mass of dry air to the mass of water vapour in the same mass of dry air when it is saturated at the same temperature and pressure, is called
A Humidity ratio
B Relative humidity
C Absolute humidity
D Degree of saturation
Which is not concerned directly with mass transfer?
A Schmidt number
B Sherwood number
C Lewis relationship
D Froude number

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