1. The purpose of evaporator is (c)
a. To absorb heat from coach and to send cooled air in to the coach.
b. To convert liquid refrigerant into vapor
c. Both (a) and (b)
Answer - c. Both (a) and (b)
a. To absorb heat from the coach and to send cooled air in to the coach
b. To draw refrigerant vapor from the cooling coil and boost the temperature and pressure of refrigerant.
c. To reject the heat of refrigerant to the water or air and to convert refrigerant vapor into liquid
d. To control an
d pump the refrigerant to the cooling coil.
Answer - a. To absorb heat from the coach and to send cooled air in to the coach
a. To absorb heat from the coach and to send cooled air in to the coach
b. To draw refrigerant vapor from the cooling coil and to boost the temperature and pressure of refrigerant
c. To reject the heat of refrigerant to the water and air and to convert refrigerant vapor into liquid
d. To control and pump the refrigerant to the cooling coil.
Answer - b. To draw refrigerant vapor from the cooling coil and to boost the temperature and pressure of refrigerant
4. The purpose of condenser is to (c)
a. To absorb heat from the coach and send cooled air in to the coach
b. To draw refrigerant vapor from the cooling coil and to boost the temperature and pressure of
refrigerant
c. To reject the heat of refrigerant to the water of air and to convert refrigerant vapor in to liquid
d. To control an pump the refrigerant to the cooling coil
Answer - c. To reject the heat of refrigerant to the water of air and to convert refrigerant vapor in to liquid
5. The purpose of expansion valve is (d)
a. To absorb heat from the coach and send cooled air in to the coach
b. To draw refrigerant vapor from the cooling coil and to boost the temperature and pressure of
refrigerant
c. To reject the heat of refrigerant to the water of air and to convert refrigerant vapor in to liquid
d. To control an pump the refrigerant to the cooling coil
Answer - d. To control an pump the refrigerant to the cooling coil
a. It carries the low pressure vapor from the evaporator to the suction inlet of the compressor
b. It conveys the high pressure and high temperature refrigerant from the compressor to the condenser
c. It carries the liquid refrigerant from the liquid receiver and conves it to the expansion valve
d. It acts as a reservoir which stores the liquid refrigerant coming from the condenser and supplies it to the cooling coil according to its requirement
Answer - d. It acts as a reservoir which stores the liquid refrigerant coming from the condenser and supplies it to the cooling coil according to its requirement
7. The relative humidity for the human comfort zone is (a)
a. 40 - 60%
b. 80 - 100%
c. 20 - 40%
d. None
Answer - a. 40 - 60%
a. 23 to 25 C
b. 19 to 21 C
c. 26 to 28 C
d. None
Answer - a. 23 to 25 C
a. 23 to 25 C
b. 19 to 21 C
c. 26 to 28 C
d. None (b)
Answer - b. 19 to 21 C
a. Vapor compressor system
b. Circulation of cold water system
c. Ice activated system
d. All of the above
Answer - a. Vapor compressor system
11. The purpose of compressor in vapor compressor system is (c)
a. It extracts refrigerant gas from the evaporator coil at low pressure
b. it compresses low temperature and low pressure gas and delivers to the condenser at high pressure and high temperature
c. Both (a) and (b)
Answer - c. Both (a) and (b)
12. The purpose of dehydrator and filter used in vapor compression system is (c)
a. It removes moisture available in refrigerant system
b. It prevents particles and scales in refrigerant system
c. Both (a) and (b)
d. None
Answer - c. Both (a) and (b)
13. The purpose of high pressure cut out used in vapor compressor system is (c)
a. It stops the compressor if the pressure exceeds the pre set value
b. It protects the compressor and piping from damage
c. Both (a) and (b)
d. None
Answer - c. Both (a) and (b)
14. The purpose of condenser used in vapor compressor system is (c)
a. It cools the high pressure hot gas received from the compressor.
b. It converts high pressure gas into liquid
c. Both (a) and (b)
d. None
Answer - c. Both (a) and (b)
15. The purpose of expansion valve/capillary tube used in vapor compression system is (c)
a. It controls the rate flow of high pressure refrigerant liquid
b. It allows refrigerant liquid to evaporator at low pressure
c. Both (a) and (b)
d. None
Answer - c. Both (a) and (b)
16. The purpose of the evaporator (cooling coil) used in vapor compression system is (c)
a. It evaporates refrigerant liquid by absorbing heat from surrounding areas
b. It cools surrounding area
c. Both (a) and (b)
d. None
Answer - c. Both (a) and (b)
17. Formula for converting centigrade into foreign heat (b)
a. 5/9 (F-32)
b. 9/5 (C +32)
c. 9/5 (F-32)
d. 5/9 (C +32)
Answer - b. 9/5 (C +32)
18. Formula for converting foreign heat into centigrade (a)
a. 5/9 (F-32)
b. 9/5 (C +32)
c. 9/5 (F-32)
d. 5/9 (C +32)
Answer - a. 5/9 (F-32)
19. The normal body temperature of human being is (c)
a. 37 C
b. 98.6 F
c. Both (a) and (b)
d. None
Answer - c. Both (a) and (b)
20. The danger for the human body, if the temperature fails below (a)
a. 98 F
b. 98.6 F
c. 105.6 F
d. None
Answer - a. 98 F
21. The danger for the human body, if the temperature fails below (a)
a. 36.5 C
b. 37 C
c. 40.5 C
d. None
Answer - a. 36.5 C
22. The danger for the human body, if the temperature increase above (a)
a. 40.5 C
b. 37 C
c. 36.5 C
d. None
Answer - a. 40.5 C
23. The danger for the human body, if the temperature increase above (c)
a. 98 F
b. 98.6 F
c. 105.6 F
d. None
Answer - c. 105.6 F
24. If the relative humidity is below 30% the result will be (c)
a. Mucous membranes
b. Skin surface becomes too dry
c. Both (a) and (b)
d. None
Answer - c. Both (a) and (b)
25. If the relative humidity is above 70% the result will be (c)
a. Clammy sensation
b. Sticky sensation
c. Both (a) and (b)
d. None
Answer - c. Both (a) and (b)
26. For summer air conditioning the relative humidity should not be more than (b)
a. 40%
b. 60%
c. 75%
d. 90%
Answer - b. 60%
27. For winter air conditioning the relative humidity should not be less than (a)
a. 40%
b. 60%
c. 75%
d. 90%
Answer - a. 40%
28. The duct is made of (e)
a. Galvanized Iron
b. Aluminum
c. Fiber glass
d. Cement asbestos
e. Any one of the above
Answer - e. Any one of the above
29. Capillary tube id used in (a)
a. Hermitically sealed units
b. Open type AC units
c. Semi open type AC units
d. None
Answer - a. Hermitically sealed units
30. An evaporator is also known as (d)
a. Freezing coil
b. Cooling coil
c. Chilling coil
d. All of the above
Answer - d. All of the above
a. Freezing coil
b. Cooling coil
c. Chilling coil
d. All of the above
Answer - d. All of the above
32. Condenser is used in the _______ pressure side of the refrigerant system (b)
a. Low
b. High
c. Medium
d. None
Answer - b. High
a. Compressor
b. Condensation
c. Expansion
d. Evaporation
Answer - a. Compressor
a. compressor
b. Condenser
c. Expansion valve
d. Evaporator
Answer - b. Condenser
35. Dry bulb temperature is (a)
a. The temperature indicated by a temperature with a clean, dry sensing element that is shielded from radiation effects.
b. The temperature measured by a thermometer with its bulb covered bt a wick wetted with distilled water exposed to a current of rapidly moving air.
c. An arbitrary index of the degree of warmth or cold felt by the human body in response to a combination of the temperature, humidity and movement of air
d. None
Answer - a. The temperature indicated by a temperature with a clean, dry sensing element that is shielded from radiation effects.
36. Wet bulb temperature is (b)
a. The temperature indicated by a thermometer with a clean, dry sensing element that is shielded from radiation effects
b. The temperature measured by a thermometer with its bulb covered by a wick wetted with distilled water exposed to a current of rapidly moving air,
c. An arbitrary index of the degree of warmth or cold felt by the human body in response to a combination Of the temperature, humidity and movement of air
d. None
Answer - b. The temperature measured by a thermometer with its bulb covered by a wick wetted with distilled water exposed to a current of rapidly moving air,
37. The air conditioning system depends on its action on the (c)
a. Latent heat principle
b. Expansion principle
c. Both (a) and (b)
d. none
Answer - c. Both (a) and (b)
38. Latest heat principle is (c)
a. Any substance is passing from the liquid to gaseous state absorbs a specific quantity of heat at constant temperature.
b. Any substance is passing from the gaseous to liquid state gives up a specific quantity of heat at constant temperature.
c. Both (a) & (b)
d. None.
Answer - c. Both (a) & (b)
39. Latest heat principal is applied for (c)
a. Evaporator
b. Condenser
c. Both (a( & (b)
d, None
Answer - c. Both (a( & (b)
40.Psychometric chart is (d)
a. The fundamental tool of air conditioning engineer.
b. The science involving thermo dynamic properties of moist air
c. The changes occurring in humid air when it is subjected to various air conditioning process can be
traced.
d. All the above.
Answer - d. All the above.
a. Dry bulb temperature
b. Wet bulb temperature
c. Dew point temperature
d. Humidity
e. Total heat (enthalpy)
f. All the above.
Answer - f. All the above.
42. Refrigerant used in air condition should be (d)
a. Non-irritating
b. non-poisonous
c. Non-inflammable
d. All the above.
Answer - d. All the above.
43. Refrigerant used in air condition system should not have (c)
a. Corrosive action
b. Disagreeable odor
c. Both (a) & (b)
d. None
Answer - c. Both (a) & (b)
44. Refrigerant used in air condition system (d)
a. Leak detection should be easy and simple.
b. Latent heat of vaporization should be large.
c. The volume of vapor for given weight should be slightly above atmosphere
d. All the above.
Answer - d. All the above.
45. The refrigerant used in AC system (d)
a. Must be capable of being liquefied at condensing temperature.
b. Must not solidify at any temperature with in the range of working.
c. The vapor pressure should be slightly above atmosphere.
d. All the above.
Answer - d. All the above.
46. The purpose of air condition is (e)
a. Temperature control
b. Humidity control
c. Air movement and circulation d. Air filtering, cleaning and purification
e. All the above.
Answer - e. All the above.
47. The range of temperature for year round human comfort is (a)
a. 22.8º to 25ºC
b. 27º to 29ºC
c 15º to 17ºC
d. None.
Answer - a. 22.8º to 25ºC
48. The range of air motion for year round human comfort is (a)
a. 5m/min to 8m/min
b. 15m/min to 20m/min
c. 25m/min to 8m/min
d. None.
Answer - a. 5m/min to 8m/min
49.The unit for the capacity of air conditioning is in (a)
a. Ton of refrigeration
b. Kilograms
c. Founds d. None
Answer - a. Ton of refrigeration
50. One ton of refrigeration is equal to (a)
a. 288000 Btu/24 hr
b. 144000 Btu/ 24 hr
c. 72000 Btu/ 24 hr
d. None.
Answer - a. 288000 Btu/24 hr
51. One ton of refrigeration is equal to (a)
a. 12000 Btu/ hr
b. 6000 Btu/ hr
c. 2000 Btu/ hr
d. None.
Answer - a. 12000 Btu/ hr
52. One ton of refrigeration is equal to (a)
a. 200 Btu/ min
b. 100 Btu/ hr
c. 50 Btu/ hr
d. None.
Answer - a. 200 Btu/ min
53. One ton of refrigerant equals to (c)
a. 72000 Kcal/ 24 hrs
b. 288000 BTU/24 Hrs
c. Both (a) & (b)
d. None.
Answer - c. Both (a) & (b)
54. One ton of refrigerant equals to (c)
a. 3000 Kcal/ hrs
b. 12000 BTU/ Hrs
c. Both (a) & (b)
d. None.
Answer - c. Both (a) & (b)
55. One ton of refrigeration is equal to (c)
a. 50 Kcal/min
b. 200 BTU for minute
c. Both (a) & (b)
d. None.
Answer - c. Both (a) & (b)
56. One ton of refrigerant is (d)
a. A machine having its capacity to produce cooling effect of 200 BTU/min or 50 Kcal per min.
b. A machine having its capacity to procure cooling effect of 12000 BTU/ hours or 3000 Kcal/per Hrs.
c. Removes the heat at the rate of 3000 Kcal/hr or 50 kcal/min
d. All of the above.
Answer - d. All of the above.
57. Refrigerant is a (c)
a. Substance which is circulated in a refrigeration system to reject heat
b. Substance which is circulated in a refrigeration system to absorb heat
c. Both (a) & (b)
d. None.
Answer - c. Both (a) & (b)
58. R22, refrigerants comes under group of (a)
a. HCFC
b.HFC
c. Both (a) & (b)
d. None
Answer - a. HCFC
59. 134a refrigerant comes under the group of (b)
a. HCFC
b. HFC
C. Both (a) & (b)
d. None
Answer - b. HFC
60. HCFC Stands for (a)
a. Hydro chloro, flouro carbon b. Halo chloro flouro carbon
c. Both (a) & (b)
d. none
Answer - a. Hydro chloro, flouro carbon b. Halo chloro flouro carbon
61. HCF Stands for (a)
a. Hydro flouro carbon
b. halo flouro carbon
c. Both (a) & (b)
d. none
Answer - a. Hydro flouro carbon
62. The moisture in AC systems causes (e)
a. Corrosion
b. Sludge
c. Amalgam
d. Freeze-up
e. All the above.
Answer - e. All the above.
63. Corrosion caused due to moisture in air condition systems results (a)
a. Damage the metallic components
b. Reduce the lubrication properties of the oil.
c. Increase the lubrication properties of the oil.
d. None
Answer - a. Damage the metallic components
a. Increase the lubrication properties of the oil.
b. Reduce the lubrication properties of the oil.
c. Blocks flow of refrigerant
d. None.
Answer - c. Blocks flow of refrigerant
a. Damage the metallic components
b. Blocks flow of refrigerant
c. Reduce the lubrication properties of the oil
d. none.
Answer - c. Reduce the lubrication properties of the oil
66. Freeze up caused due to moisture/water at capillary in AC system results. (c)
a. Damage the metallic components
b. Reduce the lubrication properties of the oil
c. Blocks flow of refrigerant
d. All of the above.
Answer - c. Blocks flow of refrigerant
67. The moisture in the AC system can be eliminate by (b)
a. Blowing dry air/nitrogen through the system
b. Pulling vacuum through the system
c. Heating the system to high temperature, while pulling vacuum, simultaneously
d. All of the above.
Answer - b. Pulling vacuum through the system
68. The suction pressure of the system lower than the normal, the causes are (e)
a. An obstruction in the flow of system
b. Failure of blower fan, filters
c. Rate of flow of refrigerant in the system is low
d. Electronic thermostats are not functioning
e. All the above.
Answer - e. All the above.
69. Suction pressure of the system is higher than the normal, the reasons may be (d)
a. Excess load on the evaporator
b. Expansion value defective
c. Compressor speed low
d. All the above
Answer - d. All the above
70. The cooling in the coach is not sufficient, the reasons may be (e)
a. Compressor not getting loaded/poor effiance
b. Too little gas or air may have accumulated in the system
c. Condenser, fresh/return filters, evaporator dirty/ choked
d. Setting of expansion value disturbed
e. All the above.
Answer - e. All the above.
71. Purging means (a)
a. Expelling all the air in the system by admitting gas
b. admitting air into the system
c. Admitting refrigerant into the system
d. None.
Answer - a. Expelling all the air in the system by admitting gas
72. Condenser head pressure is lower than the normal, the reason is (d)
a. Less gas in the system
b. Gas leakage in the system
c. Expansion value/ evaporator/ Compressor suction strainer choked
d. All of the above.
Answer - d. All of the above.
73. Condenser head pressure is higher than the normal, the reason is (d)
a. Condenser fans are not working properly
b. Air in the system
c. Excessive gas in the system
d. All of the above.
Answer - d. All of the above.
74. Capillary tube is also called as (d)
a. Condenser
b, Evaporator
c. Compressor
d. Expansion value
Answer - d. Expansion value
75 The function of capillary tube is same as. (d)
a. Condenser
b, Evaporator
c. Compressor
d. Expansion valu
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