A shpere, a cube and a disc all of the same material, quality and volume are heated to 900K and left in air. Which of these will have the lowest rate of cooling
A.Cube
B.Disc
C.Sphere
D.All will have the same rate of cooling
Category: Heat Transfer Mcqs
The value of Prandtl number for air is of the order of
A.1000
B.67
C.9.7
D.0.7
E.0.065
In case of solids, the heat transfer takes place according to
A.radiation
B.conduction
C.convection
D.Both (A) and (C)
For handling severely scaling liquids which of the following evaporator will be preferred?
A.Horizontal tube type
B.Long vertical tube type
C.Agitated film type
D.Short vertical tube
E.None of the above
What energy transformation takes place when ice and salt mixture is converted into water
A.Heat energy to kinetic energy
B.Kinetic energy to heat energy
C.Heat energy to sensible heat
D.Heat energy to latent heat
E.Heat energy to potential energy
Non-dimensional number generally involved in case of heat transfer from horizontal cylinder by natural convection is
A.Reynolds number
B.Nusselt number
C.Prandtl number
D.Grashof’s numbr
E.(B), (C) and (D) above
Elongation of a rod when heated
A.Is proportional to length
B.Is proportional to original length
C.Is inversely proportional to original length
D.Is inversely proportional to linear strain
E.Does not depend on its length
Ice is slippery when a man walks on it for
A.Its surface is smooth
B.There is no friction
C.It is very chill
D.Increase of pressure causes it to melt
E.It has lubricating qualities
All substances emit radiation, the quality and quantity depending upon the absolute temperature and the properties of the material composing the radiating body. The above statement is known as the statement of
A.Planck’s law
B.Kirchhoff’s law
C.Stefan-Bolzmann’s law
D.Law of radiation
E.D Alambert’s rule
What energy transformation takes place when ice is converted into water
A.Heat energy to kinetic energy
B.Kinetic energy to heat energy
C.Heat energy to latent heat
D.Heat energy to potential energy
E.None of the above
