| Post Name | Tradesman Refrigeration and Air Conditioning - Technical Education |
|---|---|
| Question Paper Code | 020/2025/OL |
| Category Code | 135/2024 |
| Date of Test | 25 February 2025 |
| Exam Type | Online Examination |
| Total Questions | 100 |
1
Which one of the following is not a good safety practice ?
Answer
B. Clean your hand with coolant fluid
2
The golden period of an medical emergency is
Answer
A. First 30 minutes
3
Which one of the following file have two different curve on its each side ?
Answer
D. Crossing file
4
Least count of a general purpose vernier caliper is
Answer
C. 0.001”
5
Name the drilling machine, that can be able to drill around it's pillar.
Answer
C. Radial drilling machine
6
What is the cutting angle of Tinmans shears ?
Answer
B. 87°
7
The allowance for a grooved seam is
Answer
D. Width of the seam + three times the thickness of the sheet
8
Which type of oxyacetylene flame is used for welding brass ?
Answer
B. Oxidising flame
9
Copper tube should not be used for acetylene passage, the reason is
Answer
D. Copper reacts with acetylene to form an explosive substance
10
The commercial unit of electrical energy is
Answer
B. KWH
11
A copper/aluminium disc is attached to the spindle of measuring instrument to
Answer
D. Eddy current damping
12
The instrument used to measure the insulation resistance of an installation is called
Answer
C. Megger
13
What is the formula to find synchronous speed of an AC 3 phase induction motor?
Answer
A. Synchronous speed = 120F/P
14
What is the electrical degree of 6 pole stater of motor ?
Answer
C. 1080°
15
Which device is used to test starter winding short and open fault ?
Answer
B. Internal growler
16
Which type of motor is used to provide high starting torque at variable speed ?
Answer
A. 3 phase slipering induction motor
17
What happens to a 3 phase induction motor if one phase fails during running ?
Answer
C. Motor runs slowly, finally it burns
18
The device used as voltage regulator
Answer
D. Zener diode
19
In a half wave rectifier, the load current flows for
Answer
A. Only for the positive half cycle
20
What is the purpose of a psychrometer ?
Answer
B. To measure the humidity and temperature of the air
21
What is the primary function of a compound gauge ?
Answer
B. To measure both vacuum and low side pressure of the refrigeration system
22
What does Charles's Law state about the behavior of gases ?
Answer
B. The volume of a gas is directly proportional to its absolute temperature at constant pressure
23
Which of the following is the primary purpose of a vacuum pump ?
Answer
B. To remove air and moisture from the refrigeration system
24
What does the term "Superheating" refer to in refrigeration and air conditioning systems ?
Answer
C. The temperature of the refrigerant above its boiling point in the vapor state
25
Which of the following is the correct unit of heat in the International System of Units (SI) ?
Answer
B. Joule (J)
26
What does sub-cooling refer to in a refrigeration system ?
Answer
A. The cooling of refrigerant below its saturation temperature after condensation
27
The heat transfer takes place according to
Answer
C. Second law of thermodynamics
28
What does the Coefficient of Performance (COP) of a refrigeration system represent ?
Answer
C. The ratio of the useful refrigeration effect to the work input required
29
What is the temperature of dry ice at standard atmospheric pressure ?
Answer
A. -78.5°C
30
What is the primary working principle of a vapor absorption refrigeration system ?
Answer
B. It uses an absorbent to absorb refrigerant vapor and a generator to release it
31
When using a flaring tool to create a flare on a copper tube, what is the correct angle for the flare to ensure a proper seal and connection ?
Answer
C. 45°
32
Swash plate compressors are used with
Answer
C. Automobile Air conditioners
33
In a vapour compression system, the ratio between actual volume of gas pumped and theoretically calculated volume is known as
Answer
A. Volumetric efficiency
34
The branch of science which deals with the study of lubrication in moving systems is known as
Answer
B. Tribology
35
The compressor uses whirl vein mechanism for controlling capacity
Answer
D. Centrifugal
36
Then term represents the wax separation temperature in lubricants
Answer
A. Floc point
37
How the condenser capacity is expressed ?
Answer
A. kcal/hr
38
What is the formula for finding mass flow rate in a water cooled condenser ?
Answer
C. Condenser capacity ÷ cp × dT
39
Which desiccant is filled in the drier filter of hydrocarbon charged RAC unit ?
Answer
D. Silica gel
40
During operation of mechanical draft cooling towers, the air takes away the fine droplets of water from cooling tower. This water loss is known as
Answer
D. Drift loss
41
The benefit of "Bleed off" water in cooling tower is
Answer
D. All of the above
42
Which type of cooling tower is NOT suitable for indoor installations ?
Answer
A. Natural draft
43
Which type of sensors used with the microprocessor to actuate EEV in Air conditioning system ?
Answer
B. NTC
44
In Automatic Expansion Valve, which pressure opposing the spring pressure ?
Answer
C. Suction pressure
45
Which of the following method is used to prevent flooding of compressor in RAC system using thermostatic expansion valve ?
Answer
B. Control super heat in suction line
46
Which lines are clamped together to act as a heat exchanger in a refrigeration system ?
Answer
C. Liquid line and suction line
47
Which type of evaporator is used in storage type water cooler ?
Answer
A. Plate and Tube
48
Which property is desirable for an ideal refrigerant ?
Answer
C. High latent heat value
49
What is the category of R 502 refrigerant ?
Answer
B. Azeotropes
50
Which gas is universally taken as the basic reference for GWP ?
Answer
D. CO₂
51
What is the ozone depleting potential of R 134a refrigerant ?
Answer
A. 0
52
What is the effect of releasing HCFC refrigerants to atmosphere ?
Answer
B. Increases ODP and GWP
53
What is the purpose of accumulator in a refrigerator ?
Answer
C. Prevents liquid flood back to compressor
54
Which type of motor drive is used in hermetic compressor in refrigerator ?
Answer
B. Direct drive
55
The suction line and the capillary tube are some times soldered together to
Answer
C. Serve as a heat exchanger
56
Which electrical control cuts off heating element in frost free refrigerator ?
Answer
D. Bimetal thermo
57
Which component actuates the defrost cycle in frost free refrigerator ?
Answer
A. Timer
58
What is the working condition of component during defrost cycle in inverter type frost free refrigerator ?
Answer
B. Compressor is not working
59
Why the water dispensing is stopped from water cooler ?
Answer
C. Main water supply cut off
60
Which arrangement is made in a storage type water cooler to stop the cool water from flowing upwards ?
Answer
B. Float
61
Which of the following is not present in the CSIR wiring of a visible cooler ?
Answer
A. Running capacitor
62
Which gas is used for leak testing of deep freezer before evacuation ?
Answer
C. Dry nitrogen
63
What happens if excessive ice is formed in the inner compartment of deep freezer ?
Answer
B. Acts as insulation
64
What is the reason for excess cooling in ice cubes ?
Answer
C. Thermostat is not functioning
65
Which part of the window air-conditioner allows atmospheric air entry into the condenser heated surfaces by condenser fan ?
Answer
C. Outer louvers
66
Where the normally closed contacts are internally connected in voltage relay ?
Answer
B. Across 1 and 2
67
What material is usually used for make sleeve/bush bearings in split AC ?
Answer
A. Bronze
68
What process is done first in shifting split-AC from one place to another ?
Answer
C. Pump down
69
What is the major draw back of multi split-AC ?
Answer
Question Cancelled
70
What is cause of poor cooling in multi split-AC ?
Answer
A. Window or door may be open
71
Which technology is used in VFD motor control systems ?
Answer
Question Cancelled
72
Which is not an advantage of inverter technology in split AC ?
Answer
B. It saves buying cost
73
Which type of compressor is used in car air conditioner ?
Answer
C. Swash plate
74
Which type of drive is used to connect engine and car AC compressor ?
Answer
D. V belt drive
75
The AC coaches in trains are equiped with
Answer
C. RMPU
76
How many independent refrigerant circuit in one locomotive PAC unit ?
Answer
B. Two
77
Which refrigerant is used in Bus Air conditioning system ?
Answer
A. R134a
78
Which statement is true in case of an ice candy plant ?
Answer
Question Cancelled
79
Which statement is true in case of a suction service valve ?
Answer
A. In front seat position, no connection between compressor and suction line
80
What is the function of agitator used in an ice plant ?
Answer
B. Circulate secondary refrigerant to make ice quickly
81
PSC fan motors are provided with
Answer
D. Running capacitor only
82
Which are the two pressures acting in an oil pressure cutout switch ?
Answer
B. Oil pressure and suction pressure
83
Where purge valves are installed in cold storage plants ?
Answer
D. Liquid receiver
84
Which refrigerant has the highest value of latent heat of evaporation ?
Answer
C. R717
85
Humidification process is indicated in psychrometric chart by
Answer
D. Vertical line
86
Horizontal lines in psychrometric chart indicates
Answer
A. Dew point temperature
87
Which statement is true in saturated condition of air ?
Answer
C. Wet bulb temperature equals to dry bulb temperature
88
The dry bulb temperature of air in a room is 30°C. Wet bulb temperature is 25°C and dew point temperature is 22°C. What will be the wet bulb depression ?
Answer
D. 5°C
89
Which secondary refrigerant is used in chiller air conditioning system ?
Answer
A. R718
90
FCU in centralised air conditioning means
Answer
C. Fan Coil Unit
91
The dry bulb temperature of ambient air is 35°C. Wet bulb temperature is 30°C what will be the approach of cooling tower if the outlet water temperature is 28°C ?
Answer
B. 2°C
92
The sensing bulb of thermostatic expansion valve used in package AC is clamped to
Answer
B. Suction line
93
Which are the two thermodynamic processes done in winter air conditioning ?
Answer
B. Heating and humidification
94
The flow of air in radial fan is
Answer
C. Flows perpendicular to the axis
95
What is the expansion of HVAC ?
Answer
D. Heating Ventilation and Air Conditioning
96
How velocity pressure in a duct is calculated ?
Answer
B. Total pressure – Static pressure
97
Which part controls the air flow through a duct ?
Answer
D. Damper
98
Efficiency of absolute filter is
Answer
A. 99.97%
99
At what pressure drop, hepa filters are to be replaced ?
Answer
D. 50 MMWG
100
In a rectangular duct long side (width) is 500 mm and short side (height) is 300 mm. What will be the aspect ratio of the duct ?
Answer
B. 5 : 3
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