Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning

1. 

Which of the following refrigerant has the maximum ozone depletion potential in the stratophere?

A. Ammonia
B. Carbon dioxide
C. Sulphur dioxide
D. Flourine

Answer: Option D

Explanation:

No answer description available for this question. Let us discuss.

2. 

Which of the following statement is correct?

A. The constant enthalpy lines are also constant wet bulb temperature lines.
B. The wet bulb and dry bulb temperature are equal at saturation condition.
C. The wet bulb temperature is a measure of enthalpy of moist air.
D. all of the above

Answer: Option D

Explanation:

No answer description available for this question. Let us 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.

A. Correct
B. Incorrect

Answer: Option A

Explanation:

No answer description available for this question. Let us discuss.

4. 

In electrolux refrigerator

A. ammonia is absorbed in hydrogen
B. ammonia is absorbed in water
C. ammonia evaporates in hydrogen
D. hydrogen evaporates in ammonia

Answer: Option C

Explanation:

No answer description available for this question. Let us 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

A. one
B. two
C. three
D. four

Answer: Option C

Explanation:

No answer description available for this question. Let us discuss.

1 2 3 4 5 6 7 8 9 10 Next »