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Refrigeration Mechanic UIP - Health Services question paper 2023

Health Services

Date of test
04-04-2023
Question paper code
18/2023/OL
Category No.
315/2022
Questions
100
Answer key
Provisional Answer Key
Exam mode
Online (computer based)

Provisional key. Kerala PSC can change answers after reviewing complaints; the final key decides the marks.

See questions with answersPractise as a mock test

Source: Kerala PSC (keralapsc.gov.in) · official document· Last updated 25 Sept 2026· How we check content

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As published by the Kerala Public Service Commission.

All 100 questions with answers

Tap an option to check yourself, or open the answer. Answers follow the official Kerala PSC answer key.

  1. 1.
    Which one of the following should not be followed inside a workshop, as per the general safety rules ?
    Show answer and explanation
    Answer: B —
    A machine in motion can be left as it is, by the worker
    Leaving a machine in motion unattended violates basic workshop safety rules.
    Report a mistake
  2. 2.
    In first aid CPR stands for
    Show answer and explanation
    Answer: A —
    Cardio Pulmonary Resuscitation
    CPR stands for Cardiopulmonary Resuscitation, an emergency procedure.
    Report a mistake
  3. 3.
    The weight of an Engineer's hammer is stamped at its
    Show answer and explanation
    Answer: C —
    Cheek
    The weight of the hammer is usually stamped on the cheek to avoid damage to the face or pein.
    Report a mistake
  4. 4.
    The selection of a hacksaw blade depends upon the ________ of the metal to be cut.
    Show answer and explanation
    Answer: A —
    Shape and hardness
    Hacksaw blades are selected based on the shape and hardness of the material to be cut.
    Report a mistake
  5. 5.
    _________ is measured by using a vernier height gauge along with a dial indicator.
    Show answer and explanation
    Answer: D —
    Pitch dimension
    Pitch dimensions can be accurately measured using a vernier height gauge combined with a dial indicator.
    Report a mistake
  6. 6.
    The cutting angle of straight snips is
    Show answer and explanation
    Answer: B —
    87∘87^{\circ}
    Straight snips typically have a cutting angle of about 87∘87^{\circ}.
    Report a mistake
  7. 7.
    The joining allowance for knocked-up-joint is
    Show answer and explanation
    Answer: D —
    K=2W+3TK = 2W + 3T
    The standard joining allowance formula for a knocked-up joint is K=2W+3TK = 2W + 3T.
    Report a mistake
  8. 8.
    How much pressure you will set on the regulator for oxygen gas for fusion run with filler road on 3.15 mm thick mild steel sheet ?
    Show answer and explanation
    Answer: A —
    0.150.15 kgf/cm2^2
    For welding a 3.15 mm thick MS sheet, the recommended oxygen regulator pressure is approximately 0.150.15 kgf/cm2^2.
    Report a mistake
  9. 9.
    Which of the following is an example of plastic welding ?
    Show answer and explanation
    Answer: A —
    Forge welding
    Forge welding is a solid-state or plastic welding process.
    Report a mistake
  10. 10.
    Which error if the energy meter disc rotating continuously on no load ?
    Show answer and explanation
    Answer: D —
    Creeping error
    Creeping error is the slow continuous rotation of the energy meter disc when no load is connected.
    Report a mistake
  11. 11.
    What happens to the voltmeter if it is connected as an ammeter ?
    Show answer and explanation
    Answer: A —
    Low reading
    Due to very high internal resistance of a voltmeter, connecting it in series results in a very low current and low reading.
    Report a mistake
  12. 12.
    Which conductors are used for distribution lines ?
    Show answer and explanation
    Answer: C —
    Bare conductors
    Overhead distribution lines predominantly use bare conductors supported by insulators.
    Report a mistake
  13. 13.
    What is the advantage of stranded conductor over solid conductor ?
    Show answer and explanation
    Answer: B —
    More flexible
    Stranded conductors offer higher flexibility compared to solid conductors of the same cross-section.
    Report a mistake
  14. 14.
    Which principle the earth resistance tester works ?
    Show answer and explanation
    Answer: C —
    Fall of potential method
    Earth resistance testers operate on the fall of potential method.
    Report a mistake
  15. 15.
    Which type of single phase motor is having very high starting torque than any other type of single phase motor ?
    Show answer and explanation
    Answer: A —
    Universal motor
    Universal motors can operate on both AC and DC and possess a very high starting torque.
    Report a mistake
  16. 16.
    Which speed is called as synchronous speed in three phase induction motor ?
    Show answer and explanation
    Answer: C —
    Rotating magnetic field
    Synchronous speed refers to the speed of the rotating magnetic field in the stator.
    Report a mistake
  17. 17.
    What is the purpose of using rotor resistance starter to start three phase slip ring induction motor ?
    Show answer and explanation
    Answer: C —
    Increase the torque
    A rotor resistance starter is used to limit starting current and simultaneously increase the starting torque of a slip-ring induction motor.
    Report a mistake
  18. 18.
    Which is an active component ?
    Show answer and explanation
    Answer: D —
    Transistor
    Transistors are active components because they can amplify signals and provide power gain.
    Report a mistake
  19. 19.
    Which is the main application of SCR ?
    Show answer and explanation
    Answer: D —
    Speed control of motors
    Silicon Controlled Rectifiers (SCRs) are widely used in power control applications such as motor speed control.
    Report a mistake
  20. 20.
    Which material is used to make cutting wheel in a tube cutter ?
    Show answer and explanation
    Answer: D —
    Carbon steel
    The cutting wheel of a tube cutter is made of hardened carbon steel for durability and clean cuts.
    Report a mistake
  21. 21.
    Which instrument is used to check the clearance between cylinder wall and piston of a reciprocating compressor ?
    Show answer and explanation
    Answer: B —
    Feeler gauge
    A feeler gauge is used to measure small clearances such as between a piston and cylinder wall.
    Report a mistake
  22. 22.
    Which instrument is used to find the relative humidity of air ?
    Show answer and explanation
    Answer: C —
    Sling Psychrometer
    A sling psychrometer is used to measure relative humidity using wet and dry bulb temperatures.
    Report a mistake
  23. 23.
    How much degree angle is cut out on the face of each hole in a flare block ?
    Show answer and explanation
    Answer: A —
    45°
    Standard flaring blocks have a 45∘45^\circ angle on the face of each hole.
    Report a mistake
  24. 24.
    One calorie, is the amount of heat required to raise the temperature of 1 gram of water through
    Show answer and explanation
    Answer: D —
    1°C
    One calorie is defined as the heat required to raise the temperature of 1 gram of water by 1∘C1^\circ\text{C} (from 14.5∘C14.5^\circ\text{C} to 15.5∘C15.5^\circ\text{C}).
    Report a mistake
  25. 25.
    The pressure of a gas, which just sufficient to liquefy the gas below its critical temperature is
    Show answer and explanation
    Answer: C —
    Critical pressure
    Critical pressure is the vapor pressure at the critical temperature required to liquefy a gas.
    Report a mistake
  26. 26.
    Sub cooling is the process of reducing the temperature of liquid
    Show answer and explanation
    Answer: D —
    Refrigerant below its saturation temperature
    Subcooling refers to cooling liquid refrigerant below its saturation temperature corresponding to its pressure.
    Report a mistake
  27. 27.
    Super heating is
    Show answer and explanation
    Answer: B —
    Heating of vapour above its boiling point
    Superheating is the process of heating vapor above its saturation temperature (boiling point).
    Report a mistake
  28. 28.
    Which law of thermodynamics states that at constant volume, the absolute pressure of a given mass of a perfect gas varies directly to its absolute temperature ?
    Show answer and explanation
    Answer: C —
    Gay-lussac law
    Gay-Lussac's law states that at constant volume, pressure is directly proportional to absolute temperature (P∝TP \propto T).
    Report a mistake
  29. 29.
    Three TR is equivalent to ______ of cooling effect.
    Show answer and explanation
    Answer: A —
    10.5 KW
    1 TR = 3.5 kW, therefore 3 TR = 3×3.5=10.5 kW3 \times 3.5 = 10.5\text{ kW}.
    Report a mistake
  30. 30.
    Which refrigeration system called as expandable refrigerant refrigeration system ?
    Show answer and explanation
    Answer: B —
    Liquid gas refrigeration system
    Liquid gas systems (like expendable refrigerant systems using liquid nitrogen) discharge the refrigerant after use.
    Report a mistake
  31. 31.
    What is the name of the process in which dry ice is converted into vapour state ?
    Show answer and explanation
    Answer: C —
    Sublimation
    Sublimation is the direct transition of a substance from solid to gas without passing through the liquid phase.
    Report a mistake
  32. 32.
    Which compressor dome handles high pressure and high temperature vapour ?
    Show answer and explanation
    Answer: A —
    Hermetic rotary compressor
    In a hermetic rotary compressor, the entire shell acts as a discharge pressure dome.
    Report a mistake
  33. 33.
    The volumetric efficiency of the compressor is defined as the ratio of
    Show answer and explanation
    Answer: D —
    The suction volume to the piston displacement volume
    Volumetric efficiency is the ratio of actual volume of gas sucked into the cylinder to the piston displacement volume.
    Report a mistake
  34. 34.
    Which type of compressor is provided with slide valve mechanism for capacity control ?
    Show answer and explanation
    Answer: B —
    Screw
    Screw compressors use a slide valve mechanism for continuous capacity control.
    Report a mistake
  35. 35.
    Which part of a centrifugal compressor converts velocity pressure into static pressure ?
    Show answer and explanation
    Answer: C —
    Diffuser
    The diffuser converts the high kinetic energy (velocity pressure) of the refrigerant leaving the impeller into static pressure.
    Report a mistake
  36. 36.
    Which compressor is known as turbo compressor in air conditioning systems ?
    Show answer and explanation
    Answer: C —
    Centrifugal
    Centrifugal compressors are also referred to as turbo compressors.
    Report a mistake
  37. 37.
    Leaking tubes of a water cooled condenser are isolated using
    Show answer and explanation
    Answer: A —
    Brass plugs
    Leaking tubes in shell and tube water-cooled condensers are plugged at both ends using brass plugs.
    Report a mistake
  38. 38.
    Which type of condenser uses air and water as cooling medium ?
    Show answer and explanation
    Answer: B —
    Evaporative condenser
    Evaporative condensers utilize both air and water for rejecting heat from the refrigerant.
    Report a mistake
  39. 39.
    The process of removing accumulated minerals and unwanted materials from the tubes of a water cooled condenser is called
    Show answer and explanation
    Answer: C —
    Descaling
    Descaling is the removal of scale (mineral deposits) from water-cooled condenser tubes.
    Report a mistake
  40. 40.
    What is the name of the operation used to reduce the salt concentration in cooling tower water ?
    Show answer and explanation
    Answer: D —
    Bleed off
    Bleed-off (or blowdown) is used to control mineral concentration and salt buildup in cooling tower water.
    Report a mistake
  41. 41.
    What will be the approach of a cooling tower if the inlet water temperature is 36°c, outlet water temperature is 30°c and ambient wet bulb temperature is 25°c ?
    Show answer and explanation
    Answer: B —
    5°C
    Approach = Outlet water temperature - Ambient wet bulb temperature = 30∘C−25∘C=5∘C30^\circ\text{C} - 25^\circ\text{C} = 5^\circ\text{C}.
    Report a mistake
  42. 42.
    The range of a cooling tower is the difference between
    Show answer and explanation
    Answer: A —
    Inlet water temperature and Outlet water temperature
    Range is the difference between the warm water inlet temperature and the cooled water outlet temperature.
    Report a mistake
  43. 43.
    Equaliser tube is a part of
    Show answer and explanation
    Answer: C —
    Thermostatic expansion valve
    An external equalizer tube is used with thermostatic expansion valves to compensate for evaporator pressure drop.
    Report a mistake
  44. 44.
    Which expansion device controls the refrigerant flow according to evaporator pressure ?
    Show answer and explanation
    Answer: B —
    Automatic expansion valve
    An automatic expansion valve (constant pressure expansion valve) maintains a constant pressure in the evaporator.
    Report a mistake
  45. 45.
    Which of the following expansion device cannot change the quantity of refrigerant according to the load ?
    Show answer and explanation
    Answer: D —
    Capillary tube
    A capillary tube is a fixed-restriction expansion device and cannot adjust refrigerant flow based on varying load conditions.
    Report a mistake
  46. 46.
    Operating temperature of frosting type evaporator is
    Show answer and explanation
    Answer: A —
    Below 32°F
    Frosting evaporators operate below 32∘F32^\circ\text{F} (0∘C0^\circ\text{C}), causing moisture to freeze on the coil surface.
    Report a mistake
  47. 47.
    What is the other name of bare tube coil evaporator ?
    Show answer and explanation
    Answer: C —
    Prime surface evaporator
    Bare tube evaporators are also called prime surface evaporators.
    Report a mistake
  48. 48.
    Which type of evaporator is used in direct cool refrigerator ?
    Show answer and explanation
    Answer: A —
    Plate type
    Direct cool domestic refrigerators commonly use roll-bond plate type evaporators.
    Report a mistake
  49. 49.
    Which component provide necessary pumping action to refrigerant in direct cool refrigerator ?
    Show answer and explanation
    Answer: D —
    Compressor
    The compressor circulates and pumps the refrigerant through the system.
    Report a mistake
  50. 50.
    Which of the following statement is correct about the desirable property of refrigerant ?
    Show answer and explanation
    Answer: B —
    It must have high latent heat value
    A good refrigerant should have a high latent heat of vaporization to provide more cooling per unit mass.
    Report a mistake
  51. 51.
    Which of the following statement is correct about the heat insulating material ?
    Show answer and explanation
    Answer: B —
    It must have low heat conductivity
    Thermal insulation materials must possess low thermal conductivity to minimize heat transfer.
    Report a mistake
  52. 52.
    Which part meter and regulate the pressure of refrigerant admitted to the evaporator ?
    Show answer and explanation
    Answer: C —
    Capillary tube
    The capillary tube acts as an expansion device that meters and reduces the pressure of the liquid refrigerant entering the evaporator.
    Report a mistake
  53. 53.
    Which part protect the compressor from the damage due to the high current consumption ?
    Show answer and explanation
    Answer: A —
    OLP
    The Overload Protector (OLP) protects the compressor motor from overheating and high current draw.
    Report a mistake
  54. 54.
    Which substance is known as heat carrying medium in refrigeration system ?
    Show answer and explanation
    Answer: B —
    Refrigerant
    Refrigerants act as the working fluid that absorbs and rejects heat in a refrigeration system.
    Report a mistake
  55. 55.
    Which one is example of primary refrigerant ?
    Show answer and explanation
    Answer: C —
    Ammonia
    Ammonia is a primary refrigerant that undergoes phase change in the refrigeration cycle.
    Report a mistake
  56. 56.
    What is the chemical name of R134a refrigerant ?
    Show answer and explanation
    Answer: D —
    Tetrafluoroethane
    R134a is 1,1,1,2-Tetrafluoroethane (CF3CH2FCF_3CH_2F).
    Report a mistake
  57. 57.
    What is the boiling point of isobutene refrigerant (R600a) ?
    Show answer and explanation
    Answer: C —
    −12°C
    The normal boiling point of R600a (isobutane) is approximately −11.7∘C-11.7^\circ\text{C} (around −12∘C-12^\circ\text{C}).
    Report a mistake
  58. 58.
    What is the normal ratio of R600a and R290 refrigerant in HC blend ?
    Show answer and explanation
    Answer: A —
    50:50
    Certain hydrocarbon refrigerant blends commonly combine R600a and R290 in a 50:50 ratio.
    Report a mistake
  59. 59.
    Which lubricant is used with R134a Refrigerant ?
    Show answer and explanation
    Answer: D —
    Polyol ester oil
    Polyolester (POE) oil is miscible with HFC refrigerant R134a.
    Report a mistake
  60. 60.
    Which component prevent the liquid refrigerant entering the compressor ?
    Show answer and explanation
    Answer: C —
    Accumulator
    A suction line accumulator traps liquid refrigerant and prevents it from entering the compressor.
    Report a mistake
  61. 61.
    Which type of Vacuum pump can generate a vacuum of 20 to 50 microns ?
    Show answer and explanation
    Answer: B —
    Double stage rotary
    A two-stage (double stage) rotary vacuum pump can achieve deep vacuums down to 20 to 50 microns.
    Report a mistake
  62. 62.
    Which type of relay is used with Capacitor start capacitor run sealed compressor motor ?
    Show answer and explanation
    Answer: C —
    Potential relay
    Potential relays are commonly used with capacitor-start capacitor-run (CSCR) compressor motors.
    Report a mistake
  63. 63.
    In pump down process in split AC, where did the refrigerant stored ?
    Show answer and explanation
    Answer: A —
    Condenser
    During a pump-down operation, the refrigerant is stored in the outdoor condenser unit.
    Report a mistake
  64. 64.
    What is the GWP of R 22 Refrigerant ?
    Show answer and explanation
    Answer: D —
    1700
    The Global Warming Potential (GWP) of R22 is approximately 1700 or 1810 depending on the reference scale.
    Report a mistake
  65. 65.
    Which refrigerant is the HFC group Zeotropic Mixture ?
    Show answer and explanation
    Answer: C —
    R407C
    R407C is an HFC zeotropic refrigerant blend.
    Report a mistake
  66. 66.
    What is the purpose of soldering the capillary tube to the suction line in frost free refrigerator ?
    Show answer and explanation
    Answer: A —
    Super heating vapour and sub cooling liquid
    Heat exchange between the liquid capillary tube and suction line superheats the suction vapor and subcools the liquid refrigerant for improved efficiency.
    Report a mistake
  67. 67.
    What is the use of desiccants in filter drier ?
    Show answer and explanation
    Answer: D —
    Absorb moisture
    Desiccants inside a filter drier are used to absorb moisture from the refrigerant.
    Report a mistake
  68. 68.
    Which type of defrosting method is used in frost free refrigerator ?
    Show answer and explanation
    Answer: A —
    Electric heater method
    Frost-free refrigerators typically use an electric defrost heater on the evaporator coil.
    Report a mistake
  69. 69.
    What is the normal drinking water temperature maintained in the water cooler ?
    Show answer and explanation
    Answer: B —
    10 to 12 °C
    Standard drinking water coolers maintain water temperatures around 10∘C10^\circ\text{C} to 12∘C12^\circ\text{C}.
    Report a mistake
  70. 70.
    In which refrigerating machine perishable foods are stored for long period ?
    Show answer and explanation
    Answer: C —
    Deep freezer
    Deep freezers maintain very low temperatures suitable for long-term storage of perishable foods.
    Report a mistake
  71. 71.
    The operation of expanding the inside diameter of a pipe to take in the outside diameter of another pipe end of same size is known as
    Show answer and explanation
    Answer: C —
    Swaging
    Swaging is the process of expanding the end of a tube so that another tube of the same size can fit inside it.
    Report a mistake
  72. 72.
    Which gas is used for leak testing and flushing the refrigeration systems ?
    Show answer and explanation
    Answer: D —
    Nitrogen
    Dry nitrogen gas is commonly used for pressure leak testing and purging/flushing refrigeration systems.
    Report a mistake
  73. 73.
    What is the purpose of providing fins on the tubes of a coil ?
    Show answer and explanation
    Answer: B —
    Extended surface for heat transfer
    Fins provide an extended surface area to enhance heat transfer between the coil and surrounding air.
    Report a mistake
  74. 74.
    Which instrument make the use of bourdon tube ?
    Show answer and explanation
    Answer: D —
    Pressure gauge
    Pressure gauges use a curved bourdon tube as the sensing element to measure pressure.
    Report a mistake
  75. 75.
    The component of Ice candy plant which circulates the brine solution throughout the brine tank is
    Show answer and explanation
    Answer: D —
    Agitator
    An agitator is used to circulate brine uniformly throughout the brine tank in an ice plant.
    Report a mistake
  76. 76.
    Refrigerant used in Ice plants is
    Show answer and explanation
    Answer: D —
    R717
    Ammonia (R717) is widely used as a refrigerant in large industrial ice and cold storage plants.
    Report a mistake
  77. 77.
    According to the order of priority, which one of the following components should be started first in an Ice plant ?
    Show answer and explanation
    Answer: C —
    Agitator motor
    The brine agitator should be started first to ensure proper circulation before starting refrigeration machinery.
    Report a mistake
  78. 78.
    Which psychrometer uses battery operated small fan ?
    Show answer and explanation
    Answer: B —
    Aspiring psychrometer
    An aspirating (aspirated) psychrometer uses a small battery-operated fan to draw air past the thermometer bulbs.
    Report a mistake
  79. 79.
    Dehumidification of air can be done only if the temperature of cooling coil is
    Show answer and explanation
    Answer: C —
    Below the dew point temperature of air
    Dehumidification occurs when air is passed over a cooling coil whose surface temperature is below the dew point temperature of the air.
    Report a mistake
  80. 80.
    GI sheets used for making ducts, are made resistant to rust by coating with
    Show answer and explanation
    Answer: A —
    Zinc
    Galvanized Iron (GI) sheets are coated with zinc to prevent rusting.
    Report a mistake
  81. 81.
    The efficiency of HEPA filter is
    Show answer and explanation
    Answer: C —
    99.97%
    High-Efficiency Particulate Air (HEPA) filters have an efficiency of at least 99.97% for 0.3-micron particles.
    Report a mistake
  82. 82.
    In automobile A/C systems the pistons are operated by
    Show answer and explanation
    Answer: C —
    Wobble plate
    Automotive A/C compressors commonly use a wobble plate (or swash plate) mechanism to drive the pistons.
    Report a mistake
  83. 83.
    Defrosting cycle is carried out in
    Show answer and explanation
    Answer: D —
    Walk in coolers
    Walk-in coolers operating at low temperatures require periodic defrost cycles for their evaporator coils.
    Report a mistake
  84. 84.
    Seasonal Fruits and Vegetables are made available round the year by
    Show answer and explanation
    Answer: D —
    Cold Storage
    Cold storage facilities preserve seasonal fruits and vegetables to make them available throughout the year.
    Report a mistake
  85. 85.
    The psychrometric process in which air is heated without any change in its specific humidity is known as
    Show answer and explanation
    Answer: D —
    Sensible heating
    Sensible heating increases the dry bulb temperature of air while keeping specific humidity constant.
    Report a mistake
  86. 86.
    FCU stands for
    Show answer and explanation
    Answer: B —
    Fan Coil Unit
    FCU stands for Fan Coil Unit in air conditioning systems.
    Report a mistake
  87. 87.
    Glass wool insulation is avoided in duct because of its
    Show answer and explanation
    Answer: C —
    High vapour transmission
    Glass wool can absorb moisture and has high vapor transmission, requiring proper vapor barriers.
    Report a mistake
  88. 88.
    H.E.P.A. Filter stands for
    Show answer and explanation
    Answer: A —
    High Efficiency Particulate Air Filter
    HEPA stands for High Efficiency Particulate Air filter.
    Report a mistake
  89. 89.
    Magnetic clutch is used in
    Show answer and explanation
    Answer: C —
    Car Air Conditioning Systems
    A magnetic clutch connects and disconnects the automotive A/C compressor from the engine belt drive.
    Report a mistake
  90. 90.
    Insulating materials used for cold storage must have
    Show answer and explanation
    Answer: A —
    Low thermal conductivity
    Insulating materials for cold storage must possess low thermal conductivity to prevent heat leakage.
    Report a mistake
  91. 91.
    The dry bulb temperature lines in psychrometric chart are
    Show answer and explanation
    Answer: C —
    Vertical and uniformly spaced
    Dry bulb temperature lines on a psychrometric chart are vertical (or nearly vertical) and uniformly spaced.
    Report a mistake
  92. 92.
    Desert Cooler or Evaporative Cooler is an application of which of the following psychrometric process ?
    Show answer and explanation
    Answer: C —
    Cooling and humidification
    An evaporative cooler provides simultaneous cooling and humidification (adiabatic saturation).
    Report a mistake
  93. 93.
    In a Package A/C, the sensing bulb of thermostat which cycles the compressor is located at the
    Show answer and explanation
    Answer: A —
    Air entry side of the cooling coil
    The thermostat sensing bulb in a package A/C is placed at the air entry side of the cooling coil to monitor return air temperature.
    Report a mistake
  94. 94.
    The instrument used to measure total pressure inside the duct is
    Show answer and explanation
    Answer: D —
    Pitot tube manometer
    A Pitot tube combined with a manometer is used to measure total, static, and velocity pressures in a duct.
    Report a mistake
  95. 95.
    Air filters are used in
    Show answer and explanation
    Answer: D —
    Air conditioning systems
    Air conditioning systems utilize air filters to clean circulated air.
    Report a mistake
  96. 96.
    The excessive dehydration of stored food products inside a cold storage happens if the air inside the cold storage is having
    Show answer and explanation
    Answer: A —
    Low relative humidity and high air velocity
    Low relative humidity and high air velocity increase moisture evaporation from stored food, causing excessive dehydration (shrinkage).
    Report a mistake
  97. 97.
    In central air conditioning plants, liquid receiver is located at
    Show answer and explanation
    Answer: B —
    Outlet of condenser
    The liquid receiver is installed right after the condenser outlet to store liquid refrigerant.
    Report a mistake
  98. 98.
    Compressor cut out off by HP cut out in Package AC can be caused due to
    Show answer and explanation
    Answer: C —
    Dirty condenser
    A dirty condenser restricts heat rejection, raising high-side pressure and triggering the High Pressure (HP) cutout.
    Report a mistake
  99. 99.
    Velocity pressure of air inside a duct is the
    Show answer and explanation
    Answer: C —
    Difference between static and total pressure
    Velocity pressure is the difference between total pressure and static pressure inside the duct.
    Report a mistake
  100. 100.
    The lubricant oil used with R134a refrigerant is
    Show answer and explanation
    Answer: B —
    POE oil
    Polyol Ester (POE) oil is the standard synthetic lubricant used with HFC-134a refrigerant.
    Report a mistake

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