Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning

21.
According to Prevost's theory of exchanges, every body irrespective of its temperature continuously emit heat radiations to the surrounding bodies and at the same time receives heat radiations from the surrounding bodies.
True
False
Answer: Option
Explanation:
No answer description is available. Let's discuss.

22.
In a boot-strap air evaporative cooling system, the evaporator is provided
between the combustion chamber and the first heat exchanger
between the first heat exchanger and the secondary compressor
between the secondary compressor and the second heat exchanger
between the second heat exchanger and the cooling turbine
Answer: Option
Explanation:
No answer description is available. Let's discuss.

23.
According to Stefan-Boltzmann law, the total radiation from a black body per second per unit area is directly proportional to the
absolute temperature
square of the absolute temperature
cube of the absolute temperature
fourth power of the absolute temperature
Answer: Option
Explanation:
No answer description is available. Let's discuss.

24.
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 freezing point
Answer: Option
Explanation:
No answer description is available. Let's discuss.

25.
The thermal diffusivity for gases is generally __________ those for liquids.
equal to
less than
greater than
Answer: Option
Explanation:
No answer description is available. Let's discuss.