In a thermal power plant, cooling towers are used to cool
A.steam
B.condensed wate
C.circulating
D.All of the above
Category: Heat Transfer Mcqs
Which variety of steel may be expected to have lowest value of thermal conductivity?
A.High carbon steel (0.83% C)
B.Low nickel steel (1.37% Ni)
C.Low chromium steel (0.46% Cr)
D.High chromium steel (0.26% Cr)
E.Chromium nickel steel (9% Ni, 18% Cr)
In case of a body transparent to thermal radiation
A.absorptivity = 1
B.reflectivity = 1
C.absorptivity = reflectivity = 0
D.transmissibility = 0
A body cools from 80?C to 70?C in 10 minutes. The time taken by the body for further cooling to 60?C will be
A.5 minutes
B.7 minutes
C.10 minutes
D.Less than 10 minutes
E.More than 10 minutes
Floating heads are provided in heat exchangers to
A.Increase the pressure drop
B.Reduce the pressure drop
C.Facilitate maintenance
D.Regulate the flow
E.Avoid deformation of tubes due to thermal expansion
Three rods one made of glass, one of pure aluminium and one made of wrought iron are heated to 150?C. All the rods are 15 mm in diameter and 300 mm long. The lowest temperature at the free end of the rods will occur in case of
A.Aluminium rod
B.Wrought iron rod
C.Glass rod
D.Temperature will be same for all the three rods at free end
E.Temperature will depend on the surrounding air temperature
The mass of water vapour per kg of the pressure of saturated vapour at the air is known as
A.Specific humidity
B.Relative humidity
C.Molar humidity
D.Humidity ratio
E.None of the above
For which fluid combination the value of overall heat transfer coefficient will be least?
A.Feed water heaters
B.Alcohol condensers
C.Air to heavy tars
D.Air condensers
Entrainment separator is used in evaporators to
A.Increase the boiling point
B.Reduce the boiling point
C.Prevent foaming
D.Separate liquid droplets from vapour
E.Discharge mud and other impurities
Essential requirement for the transfer of heat from one body to another is
A.Both bodies must be solids
B.Both bodies must be in contact
C.Temperatures of the two bodies must be different
D.One of the bodies must have internal source of heat generation
E.All of the above
