| Post Name | Refrigeration Mechanic (HER) |
|---|---|
| Department | Health Services |
| Question Paper Code | 115/2026/OL |
| Category Code | 457/2025 |
| Date of Test | 4 June 2026 |
| Exam Type | Online Examination |
| Total Questions | 100 |
1
What "A" denotes in ABC of ļ¬rst aid ?
Answer
B. Air way
2
Depending upon the nature of hazard, the PPE (Personal Protective Equipment) is broadly divided into how many categories ?
Answer
C. 2
3
What operation is carried out in a Gang Drilling Machine ?
Answer
A. Successive operation of drilling
4
Which chisel is used for cutting oil grooves ?
Answer
D. Half round nose chisel
5
Where will be the weight of the hammer stamped ?
Answer
C. Cheek
6
Why burr form on the underside of the sheet metal while shearing ?
Answer
B. Excessive clearance
7
Name the tool used to make ļ¬uid tight joint in riveting ?
Answer
A. Fullering tool
8
What will cause if the nozzle touches the molten pool ?
Answer
D. Back ļ¬re
9
Why the cylinder keys are not removed from the cylinder while welding ?
Answer
A. To close quickly in case of ļ¬re
10
Low resistance can be measured by using following methods i. Voltmeter and Ammeter method ii. Wheatstone bridge method iii. Kelvin bridge iv. Shunt type ohm meter
Answer
C. i, iii and iv only
11
Why permanent magnet moving coil type electrical measuring instruments having uniform scale ?
Answer
B. Deļ¬ecting torque is directly proportional to the current in the coil
12
What is/are the eļ¬ect of open in series circuit ? i. No current ļ¬ows in the circuit ii. No voltage appear across the open iii. No device in the circuit will function iv. Total supply voltage/source voltage appear across the open
Answer
D. i, iii and iv only
13
What will be the eļ¬ect if the rotor winding of a slip ring induction motor is open circuited at the time of starting ?
Answer
C. Motor will not run
14
What is the function of centrifugal switch in capacitor start capacitor run motor ?
Answer
B. Disconnect starting capacitor
15
How can be change the direction of rotation of a capacitor start induction run motor ?
Answer
D. Interchange the terminals of either starting winding or main winding
16
What are the essential components of a fully automatic star delta starter ?
Answer
A. 3 contactors, 1 overload relay and 1 timer
17
Which parts of a DOL starter are connected through control wiring ?
Answer
B. ON and OFF push button, overload relay contact, auxiliary contacts of contactor and contactor coil
18
How many electrons are there in the outer most shell of a semiconductor atom ?
Answer
B. 4
19
Which are the terminals of UJT ?
Answer
B. Base1, Base2 and Emitter
20
A compressor coupled to a motor externally is called
Answer
C. Open type compressor
21
Sub-cooling is
Answer
A. cooling liquid below its condensing point
22
In vapour compression refrigeration system, at entrance to which component the working ļ¬uid is superheated vapour
Answer
B. Condenser
23
What is the cause of burn out of hermetically sealed refrigerant compressors ?
Answer
D. All of the above
24
The sensing bulb of the thermostatic expansion valve is located at the
Answer
A. Exit of the evaporator
25
Which of the following is not a factor aļ¬ecting the capacity of evaporator ?
Answer
D. Evaporator pressure
26
Materials form deposits inside the condenser water tubes is called
Answer
C. Water fouling
27
Which Relay is used in capacitor start, capacitor run, (CSR) compressor motor ?
Answer
A. Voltage relay
28
In a refrigeration system, why are expansion devices located closer to the evaporator ?
Answer
B. To minimize the heat gain
29
The required heat for the change in state of any substance is called
Answer
A. Latent heat
30
Coeļ¬cient of Performance (COP) of a refrigerating cycle is an expression of the cycle eļ¬ciency, state the unit at Coeļ¬cient of Performance (COP)
Answer
D. No unit
31
Which of the following indicates the thickness of compressor oil ?
Answer
A. Viscosity
32
The gas strictly obeys all the gas law under all condition of temperature and pressure is called
Answer
D. Perfect gas
33
What is the name of instrument used to check high resistance ?
Answer
A. Megger
34
In a refrigerating machine, heat rejected is ___________ heat absorbed.
Answer
C. Greater than
35
Where the thermal bulb is ļ¬xed in Frost free refrigerator ?
Answer
D. Last coil of evaporator
36
Under charging of a refrigeration system
Answer
A. Reduces capacity of the system
37
In induced draft cooling tower fan used at the
Answer
A. Top
38
Which method of refrigeration system is adopted in Frost free refrigerator ?
Answer
A. Vapour compression
39
If the condenser gets partially choked then
Answer
B. Compressor discharge pressure will increase
40
The diļ¬erence in the temperature of the cold water and the wet bulb temperature of surrounding air in the cooling tower is called
Answer
B. Cooling tower approach
41
Piercing pliers is used for
Answer
C. Recovering gas by making holes in tube
42
The eļ¬ciency of a cooling tower depends upon
Answer
B. Wet bulb temperature
43
The permanent hardness of water can be removed by
Answer
C. By chemical treatment
44
An important characteristic of absorption system of refrigeration is
Answer
B. Quiet operation
45
One Ton of refrigeration is equal to the refrigeration eļ¬ect corresponding to melting of 1000 Kg of ice
Answer
C. In 24 hours
46
Centrifugal compressor working principle is
Answer
A. Conservation of kinetic energy into pressure energy
47
Oil separator is ļ¬tted between
Answer
C. Compressor and condenser
48
What is the chemical name of R-134a refrigerant ?
Answer
A. Tetra ļ¬uoro ethane
49
What is the chemical formula for R-22 refrigerant ?
Answer
D. CHClF2
50
Which one is a HFC refrigerant ?
Answer
B. R-410A
51
What is the boiling point of R-134a refrigerant ?
Answer
C. -26.2Ā°C
52
Which one is an Azeotrope refrigerant ?
Answer
A. R-504
53
Which tubes are act as heat exchanger in refrigerator ?
Answer
B. Capillary and Suction tube
54
Which two terminals reads the high resistance while testing refrigerator compressor ?
Answer
C. Running and Starting
55
What is the reason for "ļ¬lter drier sweating" in refrigerator ?
Answer
D. Moisture in the system
56
Which device is used to equalize the system pressure in frost free refrigerator ?
Answer
C. Capillary tube
57
Which type of evaporator is used in frost free refrigerator ?
Answer
A. Fins and Tube
58
What is the advantage of inverter refrigerator ?
Answer
C. High energy eļ¬ciency
59
What is the reason for poor condensation in water cooler ?
Answer
B. Fan blade bent or Crack
60
What is the causes for unit trips high current in water cooler ?
Answer
D. Compressor winding weak
61
What is the function of relay used in visible cooler ?
Answer
B. To disconnect the Starting winding
62
What is the reason for "ice build up on the evaporator" in deep freezer ?
Answer
C. Leaky door gasket
63
What is the reason for "No cooling" in deep freezer ?
Answer
D. Leak in the system
64
What is the causes of "No ice production" in ice cube machine ?
Answer
A. No water supplied to unit
65
What is the reason for "excessive frost on evaporator coil" in window air-conditioner ?
Answer
B. Air ļ¬lter blocked completely
66
What is the remedy to remove moisture from the window air-conditioning system ?
Answer
C. Evacuate the system
67
Which type of relay is used in capacitor start capacitor run (CSR) compressor motor ?
Answer
D. Voltage relay
68
Which type of fan motor is used in window air-conditioner ?
Answer
C. Single phase double end shaft motor
69
What is the reason for "very high condensing temperature" in window air- conditioner ?
Answer
D. Ambient temperature is very high
70
Which type of fan is used in condensing unit of ductable split air-conditioner ?
Answer
A. Propeller fan
71
What is the function of remote control in split air-conditioner ?
Answer
C. Transmits signal to operate air-conditioner
72
What is the causes for "noisy in indoor unit" of multi split air-conditioner ?
Answer
D. Blower is loosed
73
Where the liquid refrigerant is stored in multi split air-conditioner during pump down operation ?
Answer
B. Condenser
74
Which type of compressor motor used in inverter split air-conditioner ?
Answer
D. Variable speed motor
75
A duct is said to be a low velocity duct if the velocity of air in the duct is up to
Answer
C. 600 m/min
76
In axial ļ¬ow fans the air ļ¬ows
Answer
B. Parallel to the axis of impeller
77
The commonly used refrigerant in ice plant is
Answer
C. NH3
78
The temperature maintained in the brine tank of ice plant is
Answer
D. -10Ā°C
79
The diļ¬erence between dry bulb temperature and wet bulb temperature is called
Answer
B. Wet bulb depression
80
Which of the following statements are correct ? 1. At 100% relative humidity, wet bulb temperature, dry bulb temperature, dew point temperature and saturation temperature are equal 2. For unsaturated air DPT> DBT> WBT 3. Saturation pressure corresponding to WBT is Pvs. 4. Saturation pressure corresponding to DPT is Pv.
Answer
A. 1 and 4
81
The curved lines on psychrometric chart indicates
Answer
A. Relative Humidity
82
When only sensible heat is added to sample of air, the process is represented on psychrometric chart is given by
Answer
B. Horizontal line moving towards right direction
83
Which of the following method is not used for determination of duct size
Answer
D. Static pressure method
84
A duct is made of
Answer
D. Any one of the above
85
Two fans that are diļ¬erent sizes, but have the same basicshape to their performance curves are called
Answer
A. Geometrically similar fans
86
Which of the following type of air conditioning system is adopted when the cooling capacity required is 25 TR or more ?
Answer
D. Central air conditioning system
87
The indoor unit of split air conditioning system contains the following unit
Answer
A. Evaporative coil
88
Which of the following statement is/are correct about humidiļ¬cation process i. Dry bulb temperature is constant ii. Speciļ¬c humidity is increases iii. Relative humidity decreases iv. Wet bulb temperature is constant
Answer
A. OnIy (i & ii)
89
Which of the following process is used in winter air conditioning ?
Answer
C. Heating and Humidiļ¬cation
90
Which of the following statement is/are correct about axial ļ¬ow fans ? i. Never used for duct air conditioning system ii. They are incapable of developing high pressure iii. Used for duct air conditioning system iv. Suitable for handling large volumes of air at low pressures.
Answer
B. Only (i, ii & iv)
91
Which of the following method is not used for leakage detection of CFC refrigerants ?
Answer
C. Burning candle
92
For Large commercial installations, ammonia is used as the refrigerant, because
Answer
D. All of these
93
Which of the following refrigerant widely used in larger industrial and commercial reciprocating compression systems ?
Answer
D. Ammonia
94
Human being feels comfortable when the air is at ?
Answer
A. 21Ā°C with 56% relative humidity
95
Viscous Impingement ļ¬ltration method is capable of
Answer
C. Filtering particles of 15 to 20 microns in size
96
Fine Filters are used where the ļ¬ltering required down to
Answer
A. 5-micron size
97
Which of following not a nominal capacities of Package Air Conditioner ?
Answer
A. 25 tons
98
Which of the following not a property of HFC134a ?
Answer
D. It is nonexplosive
99
During the compression of the refrigerant inside the compressor
Answer
A. the pressure and temperature rapidly increase
100
In a refrigeration system the expansion device is connected between the
Answer
B. Receiver and Evaporator
Discussion
Ask a doubt or share a tip.
No comments yet ā start the discussion.