none of these
✅ The correct answer is option D.
Heat Transfer
The refrigerant widely used in domestic refrigerators is
ammonia
carbon dioxide
sulphur dioxide
R-12
✅ The correct answer is option D.
Film coefficient is defined as the ratio of
thermal conductivity to the equivalent thickness of the film of fluid
temperature drop through the films of fluids to the thickness of film of fluids
thickness of film of fluid to the thermal conductivity
thickness of film of f
✅ The correct answer is option A.
The thermostatic expansion valve operates on the changes in the
degree of superheat at exit from the evaporator
temperature of the evaporator
pressure in the evaporator
none of the above
✅ The correct answer is option A.
The dry bulb temperature during sensible heating of air
remains constant
increases
decreases
✅ The correct answer is option B.
A grey body is one whose absorptivity does not vary with temperature and wave length of the incident ray.
TRUE
FALSE
✅ The correct answer is option A.
The horizontal and uniformly spaced lines on a psychrometric chart indicates relative humidity.
Correct
Incorrect
✅ The correct answer is option B.
A good refrigerant should have
high latent heat of vaporisation and low freezing point
high operating pressures and low freezing point
high specific volume and high latent heat of vaporisation
low C.O.P. and low fre
✅ The correct answer is option A.
The unit of thermal diffusivity is
m/hK
m/h
m2/h
m2/hK
✅ The correct answer is option C.
In a spray washing system, if the temperature of water is higher than the dry bulb temperature of entering air, then the air is
heated and dehumidified
heated and humidified
cooled and humidified
cooled and dehumidifie
✅ The correct answer is option B.