The concept of overall coefficient of heat transfer is used in case of heat transfer by

A Conduction
B Convection
C Radiation
D Conduction and convection

Correct Answer: Conduction and convection

It is used in calculating the heat transfer, typically by convection or phase transition between a fluid and a solid.
The heat transfer coefficient has SI units in watts per squared meter kelvin: $$\frac{{\text{W}}}{{{{\text{m}}^2}{\text{K}}}}$$ .
The heat transfer coefficient is the reciprocal of thermal insulance.
Bissoy MCQ
#Mechanical Engineering #Heat And Mass Transfer

Related Questions

The concept of overall coefficient of heat transfer is used in heat transfer problems of
A Conduction
B Convection
C Radiation
D Conduction and convection
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
The rate of heat transfer is a product of overall heat transfer co-efficient, the difference in temperature and the
A Heating volume
B Heat transfer area
C Nusselt number
D None of these
Which of the following is having the lowest value of overall heat transfer coefficient?
A Feed water heaters
B Air condensers
C Air to low viscosity liquids
D Steam condensers
The unit of overall coefficient of heat transfer is
A kcal/m2
B kcal/hr °C
C kcal/m2 hr °C
D kcal/m hr °C
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
In case of vertical tube evaporator, with increase in liquor level, the overall heat transfer co-efficient
A Increases
B Decreases
C Is not affected
D May increase or decrease; depends on the feed
In case of heat transfer by conduction in a hollow cylinder, __________ mean area is used to calculate the heat transfer rate.
A Geometric
B Arithmetic
C Logarithmic
D Either A, B or C
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

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