Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning

1.
Which of the following refrigerant has the maximum ozone depletion potential in the stratophere?
Ammonia
Carbon dioxide
Sulphur dioxide
Flourine
Answer: Option
Explanation:
No answer description is available. Let's discuss.

2.
Which of the following statement is correct?
The constant enthalpy lines are also constant wet bulb temperature lines.
The wet bulb and dry bulb temperature are equal at saturation condition.
The wet bulb temperature is a measure of enthalpy of moist air.
all of the above
Answer: Option
Explanation:
No answer description is available. Let's discuss.

3.
According to Stefan's law, the total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature.
Correct
Incorrect
Answer: Option
Explanation:
No answer description is available. Let's discuss.

4.
In electrolux refrigerator
ammonia is absorbed in hydrogen
ammonia is absorbed in water
ammonia evaporates in hydrogen
hydrogen evaporates in ammonia
Answer: Option
Explanation:
No answer description is available. Let's discuss.

5.
Two long parallel surfaces each of emissivity 0.7 are maintained at different temperatures and accordingly have radiation heat exchange between them. It is desired to reduce 75% of the radiant heat transfer by inserting thin parallel shields of emissivity 1 on both sides. The number of shields should be
one
two
three
four
Answer: Option
Explanation:
No answer description is available. Let's discuss.