রেফ্রিজারেশন এন্ড এয়ারকন্ডিশনিং MCQ
21. The human body feels comfortable who the heat stored in the body is.
positive
zero
negative
none
22. In vapour compresion refrigeration system, refrigerant occurs as liquid between-.
condeuser and expäision valve
compressor and evaporator
expansion valve and evaporator
compressor and condenser
23. The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy-diagram represents--
condensation of the refrigerant vapour
evaporation of the refrigerant liquid
compression of the refrigerant vapour
meltering of the refrigerant liquid
24. Clapeyron equation is applicable for registration at—
saturation point of vapour
saturation point of liquid
sublimation temperature
triple point
25. Unit of temperature in SI unit is—
The SI unit of temperature as per the International System of Unit is Kelvin which is presented by the symbol of K. The Kelvin scale ta widely accepted or used in the field of science and engineering.
Celsin
Kelvin
Furenheit
Centigrade
26. Aqua ammonia is used as refrigerant in the following type of refrigeration system--
compression
indirect
absorption
direct
27. Bull bearing is usually made from-
low carbon steel
high carbon steel
chrome steel
medium carbon steel
28. In a flooded evaporator refrigerator, an accumulator at suction of compressor is used to--
collect liquid refrigerant and prevent it from going to compressor
detect liquid in vapour
superheat the vapour
collect vapours
29. At lower temperatures and pressures, the latent heat of vapourisation of a refrigerant-
decreases
increases
remains same
depends on other factors
30. pick up incorrect statement-the
lithium bromide used in vapour absorption cycle is nonvolatile
lithium bromide plant can't operate below 0 °C
a separator is used in lithium bromide plant to remove the unwanted water vapour by condensing
concentration of solution coming out of lithium bromide generator is more in comparison to that entering the generator
31. A certain refrigerating system has a normal operating suction pressure of 10 kg/cm gauge and condensing pressure of about 67kg/cm The refrigerant used is--
Ammonia
Carbon dioxide
Freon
Brine
32. Pick up the correct statement about giving up of heat from one medium to other in ammonia absorption system-
strong solution is weak solution
weak solution to strong solution
atozng solution to ammonia vapour
ammonia vapour to weak solution
33. Where does the lowest temperature occur in a vapour compression cycle?
condenser
compressor
evaporator
expansion valve
34. An evaporator is also known as—
cooling coil
freezing coil
chilling cod
all of these
35. In a refrigeration cycle, the flow of refrigerant is controlled by –
compressor
evaporator
expansion valve
condenser
36. Efficiency of a Carnot engine is given as 80%. If the cycle direction he reversed, what will be the value of COP of reversed Carnut cycle?
125
0.5
0.25
0.8
37. Air conditioning means--
heating
cooling
dehumidifying
all of these
38. Accumulators should have adequate volume to store refrigerant charge at least-
10%
50%
25%
75%
39. The vapour pressure of refrigerant should be—
higher than atmospheric pressure
equal to atmospheric pressure
lower than atmospheric pressure
could be anything
40. The value of COP in vapour compression cycle is usually--
always less than unity
always more than unity.
equal to unity
any one of the above