Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning
Exercise :: Heat Transfer, Refrigeration and Air Conditioning - Section 5
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:
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:
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:
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
Answer: Option C
Explanation:
10.
An infinite parallel planes with emissivities e 1 and e 2 , the interchange factor for radiation from surface 1 to surface 2 is given by
Answer: Option A
Explanation: