Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning

6. 

Dry bulb temperature is the temperature of air recorded by a thermometer, when

A. it is not affected by the moisture present in the air
B. its bulb is surrounded by a wet cloth exposed to the air
C. the moisture present in it begins to condense
D. none of the above

Answer: Option A

Explanation:

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

7. 

In a spray washing system, if the temperature of water is higher than the dry bulb temperature of entering air, then the air is

A. heated and dehumidified
B. heated and humidified
C. cooled and humidified
D. cooled and dehumidified

Answer: Option B

Explanation:

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

8. 

A valve which maintains a constant degree of superheat at the end of the evaporator coil, is called

A. automatic expansion valve
B. high side float valve
C. thermostatic expansion valve
D. low side float valve

Answer: Option D

Explanation:

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

9. 

The atmospheric air at dry bulb temperature of 15°C enters a heating coil maintained at 40°C. The air leaves the heating coil at 25°C. The by-pass factor of the heating coil is

A. 0.376
B. 0.4
C. 0.6
D. 0.67

Answer: Option C

Explanation:

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

10. 

An infinite parallel planes with emissivities e1 and e2, the interchange factor for radiation from surface 1 to surface 2 is given by

A.
B.
C. e1 + e2
D. e1e2

Answer: Option A

Explanation:

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