রেফ্রিজারেশন এন্ড এয়ারকন্ডিশনিং MCQ
101. In a certain room, dry bulb temperature is 35°C and wet bulb temperature is also 35°C, the relative humdity of the room is-
80%
90%
100%
None of the above
102. The pressure at the outlet of a refrigerant compressor is called-
discharge pressure
critical pressure
hack pressure
suction pressure
103. Choose the correct statement:
A refrigerant should have low latent heat
If operating temperature of system is low, then refrigerant with low boiling point should be used
Precooling and subcooling of refrigerant are same
Superheat and sensible heat of refrigerant are same
104. The power per tonne of refrigeration is-
3.5/COP
COP/3.5
COP/ 35
3.5COP
105. যখন অ্যাবজরতিটি (∝) = 0, রিফ্লেকটিভিটি (p) = 1 এবং ট্রান্সমিটিভিটি (γ) = 0, তখন বস্তুটিকে কী বলা হবে?
কালো বস্তু
ধূসর বস্তু
ওপেক বস্তু
সাদা বস্তু
106. Air-conditioning means.....
cooling
heating
dehumidifying
all of these
107. The advantage of dry compression is that-
it permits higher speeds to be used
it permits complete evaporation in the evaporator
it results in high volumetire and mechanical efficiency
all of the above
108. Freon group of refrigerants is-
Inflammable
toxic
non-inflanzaable and toxic
non-toxic and non-inflammable
109. The absolute zero temperature is taken as-
-273°C
237°C
273°C
-237°C
110. For obtaining high COP, the pressure range of compressor should be--
high
optimum
low
any value
111. One ton of the refrigeration is-
the standard unit used in refrigeration problems
the cooling effect produced by melting 1 ton of ice
the refrigeration effect to freeze 1 ton of water at 0°C into ice at 0°C.in 24 hours
the refrigeration effect to produce 1 ton of ice at NTP conditions
112. According to joule's law, the internal energy of a perfect gas is the funciton of absolute--
density
temperature
pressure
volume
113. The suction pipe diameter of refrigerating unit compressor in comparison to delivery side is-.
bigger
smaller
equal
smaller/bigger depending on capacity
114. For proper refrigeration in a cabinet, if the temperature and vapour pressure differenc between cabinet and atmosphere is high then-
bigger cabinet should be used
smaller cabinet should be used
perfectly tight vapour seal should be used
refrigerant with lower evaporation tempera should be used
115. The coefficient of performance is the ratio of the refrigerant effect to the –
heat of compression
work done by compressor
enthalpy increase in compressor
all of the above
116. Moisture in freon refrigeration system causes-
ineffective refrigeration
high power consumption
freezing automatic regulating valve
corrosion of whole system
117. The minimum dielectric stress in a cable is at-.
conductor surface
centre of conductor
lead sheath
none of the above
118. 1 Ton of refrigeration is equivalent to heat removal rate of-
600 BTU/hr
10,000 BTU/hr
8000 BTU/hr
12,000 BTU/hr
119. Under-cooling in a refrigeration cycle-.
increases COP
decreases COP
COP remains unaltered
other factors decide COP
120. Superheating in a refrigeration cycle-
increases COP
decreases COP
COP remains unaltered
other factors decide COP