In which of the following heat exchange process, the value of overall heat transfer coefficient will be highest?
A.Air to heavy tars
B.Air to carbondioxide
C.Steam to oil
D.Steam condensers
Category: Heat Transfer Mcqs
A thin circulr disc has a concentric hole in it. On heating the diameter of hole will
A.increase
B.decrease
C.remain constant
In case of natural covection, the Nusselt number is function of
A.Reynolds number
B.Reynolds number and Prandtl number
C.Grashof’s number and Prandtl number
D.Weber number and Mach number
E.None of the above
Two bodies one hot and the other cold are kept in vacuum. What will happen to the temperature of the hot body after sometime?
A.Remains the same
B.Decreases due to convection
C.Increases due to convection
D.Increases due to radiation
E.Decreases due to radiation
Which one of the following cannot be unit of thermal conductivity?
A.Watt / m2 K
B.Kcal/m-hr?C
C.BTU/ft-h?F
D.cal/c,-sec?K
E.CHU/ft-hr?C
DBA = DAB, in case of
A.Stagnet diffusion
B.Equimolar counter diffusion
C.Either of (A) and (B) above
D.None of the above
If in a system ratios of the velocity and acceleration of the homologous particles are equal, the similarity being considered is
A.geometric similarity
B.kinematic similarity
C.thermal similarity
D.dynamic similarity
Formation of fog is due to
A.Low pressure
B.High pressure
C.Night showers
D.Humidity
E.Temperature fall of atmosphere
The density of water is maximum at
A.20?C
B.4?C
C.0?C
D.? 4?C
E.Absolute zero
A correction of LMTD is necessary in case of
A.Parallel flow heat exchanger
B.Counter current heat exchanger
C.Cross flow heat exchanger
D.All of the above
E.None of the above
