For a opaque body
A.absorptivity = 0
B.reflectivity = 0
C.absorptivity = reflectivity = 1
D.absorptivity + reflectivity = 1
Category: Heat Transfer Mcqs
Heat conduction does not occur
A.If a physical body is impermeable to any kind of rays
B.If the parts of a body are not in motion relative to one another
C.If the bodies are kept in vacuum
D.If the bodies are immersed in water
E.If the temperature difference between the bodies does not exist
In case of ideal mono-atomic gas, the ratio of specific heats would be
A.1
B.1.33
C.1.4
D.1.41
E.1.67
The ratio of heat transfer coefficient to the flow of heat per unit temperature rise due to the velocity of the fluid is known as
A.Prandtl number
B.Grashoff number
C.Stanton number
D.Weber number
The range of diffusivity of gases in cm2/sec at atmospheric pressure is
A.Less than 1
B.1
C.5 to 1
D.10 to 5
E.More than 10
Kinematic viscosity indicates
A.momentum transport by molecular friction
B.heat energy transport through conduction
C.heat evergy transport through convection
D.conversion of momentum into heat energy
Which one of the following approximates to the black body condition?
A.Ice
B.Water
C.Lamp black
D.All of the above
E.None of the above
Which evaporator is preferred for concentrating the fruit juice?
A.Long vertical tube evaporator
B.Short vertical tube evaporator
C.Agitated film evaporator
D.Zig-zag film evaporator
E.Falling film evaporator
If the amount of radiant energy received per unit area per second from the sun is measured at the Earth, Mars and Jupiter it will be
A.identical on all the three planets
B.in the decreasing order – Jupiter, Mars, Earth
C.in the increasing order – Earth, Mars, Jupiter
D.in the increasing order – Jupiter, Mars, Earth
