Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning
Exercise :: Heat Transfer, Refrigeration and Air Conditioning - Section 5
| 1. |
R-12 is generally preferred over R-22 in deep freezers since |
| A. |
it has low operating pressures | | B. |
it gives higher coefficient of performance | | C. |
it is miscible with oil over large range of temperatures | | D. |
all of the above |
Answer: Option C
Explanation:
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| 2. |
The temperature of air recorded by a thermometer, when its bulb is surrounded by a wet cloth exposed to the air, is called |
| A. |
wet bulb temperature | | B. |
dry bulb temperature | | C. |
dew point temperature | | D. |
none of these |
Answer: Option A
Explanation:
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| 3. |
During sub-cooling, sensible heat from a liquid refrigerant is removed. |
Answer: Option A
Explanation:
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| 4. |
The expression  is used for calculating relative humidity. |
Answer: Option B
Explanation:
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| 5. |
If the energy radiated per second per sq. cm. of the surface for wave lengths lying between λ, and λ + dλ is represented by (eλ.dλ), then eλ is called |
| A. |
absorptive power | | B. |
emissive power | | C. |
emissivity | | D. |
none of these |
Answer: Option B
Explanation:
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