রেফ্রিজারেশন এন্ড এয়ারকন্ডিশনিং MCQ
41. For better COP of refrigerator, the pressure range corresponding to temperature in evaporator and condemer must be-
small
equal
high
anything
42. Highest temperature refrigeration cycle should be encountered In near critical temperature of refrigerant--
above critical temperature
at critical temperature
much below critical temperature
none
43. Vapour compression refrigeration is some what like-.
Camot cycle
Rankine cycle
reversed Canet cycle
none of the above
44. The higher temperature in compression cycle occurs at-
receiver
expansion valve
evaporator
compressor discharge
45. Air refrigeration operates on—
Carnot cycle
Rankine cycle
Reversed Carnot cycle
Brayton cycle
46. Ammonia-absorption refrigeration cycle requires--
very litle work input
maximum work, input
nearly same work input as for vapour
compression cycle zero work input
47. Absorption system normally uses the following refrigerant-
Freon-11
ammonia
Freon-22
CO
48. The relative coefficient of performance is-
actual COP/theoretical COP
theoretical COP/actual COP
actual COP x theoretical COP
1-actual COP x theoretical COP
49. Domestic refrigerator working on vapour compression cycle uses the following type of expansion device-
electrically operated throttling valve
manually operated valve
thermostatic valve
capillary tube
50. A standard ice point temperature corresponds to the temperature of-.
water at 0°C
ice at-4°C
solid and dry ice
mixture of ice and water under equilibrium conditions
51. Which of the following cycles uses air as the refrigerant?
Ericsson
Carmot
Stirling
Bell-coleman
52. A domestic refrigerator has the co- efficient of performance-.
equal to 10
less than 10
more than 10
none
53. Which of the following refrigerant is highly toxic and flammable?
sulphur dioxide
Freon-12
Ammonia
Carbon dioxide
54. In refrigerator, liquid receiver is required between condenser and flow controlling device, if quantity of refrigerant for system is-
less than 2kg
more than or equal to 3.65kg
more than 10kg
there is no such consideration
55. Refrigeration in aeroplanes usually employs the following refrigerant-
Freon-11
Air
Freon-22
Ammonia
56. One of the purposes of subcooling the liquid refrigerant is to-
reduce compressor overheating
reduce compressor discharge temperature
increase cooling effect
ensure that only liquid and not the vapour enters the expansion (throttling) valve
57. During a refrigeration cycle heat is rejected by the refrigerant in a-
compressor
condenser
evaporator
expansion valve
58. Presence of moisture in a refrigerant affects the working of--
compressor
condemer
evaporator
expansion valve
59. Air refrigeration cycle is used in--
domestic refrigerators
commercial refrigerators
air-conditioning
gas liquefaction
60. The bank of tubes at the back of domestic refrigerator are-
condenser tubes
evaporator tubes
refrigerant cooling tubes
capillary tubes