Discussion
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- Question
A grey body is one whose absorptivity does not vary with temperature and wave length of the incident ray.
Options- A. True
- B. False
- Correct Answer
- True
- 1. The emissivity of a polished silver body is __________ as compared to black body.
Options- A. same
- B. low
- C. very low
- D. high Discuss
- 2. During sub-cooling, sensible heat from a liquid refrigerant is removed.
Options- A. Yes
- B. No Discuss
- 3. The mass of water vapour present in __________ is called absolute humidity.
Options- A. 1 m3 of wetair
- B. 1 m3 of dry air
- C. 1 kg of wet air
- D. 1 kg of dry air Discuss
- 4. When absorptivity (?) = 1, reflectivity (?) = 0 and transmittivity (?) = 0, then the body is said to be a
Options- A. black body
- B. grey body
- C. opaque body
- D. white body Discuss
- 5. The evaporator changes the low pressure liquid refrigerant from the expansion valve into
Options- A. high pressure liquid refrigerant
- B. low pressure liquid and vapour refrigerant
- C. low pressure vapour refrigerant
- D. none of these Discuss
- 6. The wet bulb temperature during sensible cooling of air
Options- A. remains constant
- B. increases
- C. decreases Discuss
- 7. The colour of the flame of halide torch, in case of leakage of freon refrigerant, will change to
Options- A. bright green
- B. yellow
- C. red
- D. orange Discuss
- 8. In absorption vapour systems, the refrigerant widely used is R-12.
Options- A. Correct
- B. Incorrect Discuss
- 9. In a spray washing system, if the temperature of water is higher than the dry bulb temperature of entering air, then the air is
Options- A. heated and dehumidified
- B. heated and humidified
- C. cooled and humidified
- D. cooled and dehumidified Discuss
- 10. The final relative humidity of the air during cooling and dehumidification is generally __________ than that of entering air.
Options- A. lower
- B. higher Discuss
Heat Transfer, Refrigeration and Air Conditioning problems
Search Results
Correct Answer: very low
Correct Answer: Yes
Correct Answer: 1 m3 of dry air
Correct Answer: black body
Correct Answer: low pressure vapour refrigerant
Correct Answer: decreases
Correct Answer: bright green
Correct Answer: Incorrect
Correct Answer: heated and humidified
Correct Answer: higher
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