Molecular transmission of heat is smallest in case of
A.Gases
B.Liquids
C.Liquids with impurities
D.Solids
E.Alloys
Category: Heat Transfer Mcqs
In air prelieater for boiler heat is least transferred by
A.Conduction
B.Convection
C.Conduction and convection
D.Radiation
E.Conduction, convection and radiation.
Thermal conductivity of liquids can be determined by
A.Guarded plate method
B.Searles method
C.Laby and Hercus method
D.Any of the above
E.None of the above
Which of the following provides maximum contact surface for a liquid vapour system?
A.Bubble cap tower
B.Packed tower
C.Sieve plant column
D.Wetted wall column
Heat is transferred from an electric bulb mainly by
A.Conduction
B.Convection
C.Convection and conduction
D.Radiation
E.Conduction, convection and radiation.
Non-isotropic conductivity is exhibited in case of
A.Brass
B.Steel
C.Copper
D.Lead
E.Wood
The equation ?m x T = constant represents
A.Wein’s Law
B.Kirchhoff’s law
C.Stefan Boltzmann’s law
D.None of the above
The net radiant interchange per square metre for two large parallel planes at temperatures of 1000?K and 100?K respectively, would be roughly
A.25 kcal/hr
B.75 kcal/hr
C.120 kcal/hr
D.240 kcal/hr
E.480 kcal/hr
If thermal conductivity of aluminium is say 100 units at 0?C, the thermal conductivity at 500?C will be closer to
A.20 units
B.50 units
C.100 units
D.140 units
Thermal conductivity of air at room temperature in kcal/m-hr-?C is nearly
A.0.001
B.0.005
C.0.01
D.0.05
E.0.1
