A dimensionless number representing the ratio of inertia forces to viscous forces is known as
A.Reynolds number
B.Prandtl number
C.Nusselt number
D.Mach number
E.Stanton number
Category: Heat Transfer Mcqs
The average value of thermal conductivity for air at 20?C is about
A.0.11
B.0.011
C.0.022
D.None of the above
Which one of the following is a very good insulator?
A.A hard wood board
B.A porcelain sheet
C.An asbestos sheet
D.Saw dust
Pyrometer which react to all wavelengths of incident radiant energy are known as
A.Optical pyrometers
B.Ddisappearing filament type pyrometers
C.Polarising pyrometers
D.Total radiation pyrometers
E.Multicolour pyrometers
Least value of Prandlt number can be expected in case of
A.Liquid metals
B.Salt solution
C.Sugar solution
D.Water
E.Petroleum products
Hygrometer is used to measure
A.Convective heat transfer coefficient
B.Heat exchanged due to vapour
C.Density of liquids
D.Relative humidity
E.None of the above
If the bubbles formed on a submerged hot surface get absorbed in the mass of liquid, the process of boiling is termed as
A.Nucleate boiling
B.Film boiling
C.Pool boiling
D.Any of the above
E.None of the above
The radiation from flames consists of
A.Continuous radiation from burning soot particles of microscopic and submicroscopic dimensions
B.Radiation from suspended larger particles of coal, coke or ash contributing to flame luminosity
C.Infrared radiation from water vapour and carboundioxide
D.Non-equilibrium radiation associated with the combustion process
E.All of the above
Which of the following is used as entrainer in acetic acid – water separation?
A.Methyl alcohol
B.Hexane
C.Phosphorous
D.Butyl acetate
E.Benzene.
The numerical value of which property of air generally drops with rising temperature
A.Density
B.Dynamic viscosity
C.Kinematic viscosity
D.Thermal conductivity
E.Thermal diffusivity
