Junior Instructor Mechanic Refrigeration and Air Conditioning 02/2017 Answer Key 67/2018

refrigeration

Post: Junior Instructor - Mechanic Refrigeration and Air Conditioning
Department: Industrial Training
Category Code: 02/17
Qualification: S.S.L.C + National Trade Certificate in the appropriate trade + 3 years experience, National Apprenticeship Certificate + 3 years experience; Diploma in the appropriate branch of Engineering
Question Paper Code: 67/18
Date of Test: 29-06-2018


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  1. In a refrigeration cycle, pressure is maximum __________.
    • After Expansion Valve
    • After Condenser
    • After Evaporator
    • After Compressor

  2. The Dalton’s law deals with the __________.
    • Sum partial volumes of gases
    • Sum partial temperature of gases
    • Sum partial pressure of gases
    • None of these

  3. An automatic expansion valve is based on the principle of __________.
    • Maintaining a constant degree of superheat
    • Maintaining a constant pressure in evaporator
    • Maintaining a constant temperature in the evaporator
    • Both "Maintaining a constant degree of superheat" and "Maintaining a constant pressure in evaporator"

  4. Window AC for cooling mode can be easily converted to heating mode by installing a:
    • TXV
    • RCV
    • AXV
    • Solenoid valve

  5. Approach of a cooling tower is defined as the:
    • Difference of DBT of surrounding air and temperature of water leaving the CT
    • Difference of temperature of water leaving the CT and temperature of entering water
    • Difference of temperature of water leaving the CT and WBT of surrounding air
    • None of these

  6. Temporary hardness of water can be removed by:
    • filtering
    • chemical treatment
    • boiling
    • cooling

  7. The cleaning efficiency of a fine filter is:
    • 99.9%
    • 100%
    • 80%
    • 70%

  8. Which type of fan is used in electrical motors for internal cooling?
    • Backward inclined fan
    • Backward curved fan
    • Forward curved fan
    • Radial blade fan

  9. Which senses the suction temperature in thermal electric expansion valve?
    • Transformer
    • Thermal bulb
    • Thermostat
    • Thermistor

  10. Which run capacitor is used with 1.5 TR AC?
    • 36 mfd, 220/250 V
    • 80 mfd 220/250 V
    • 36 mfd, 440/370 V
    • 80 mfd 440/370 V

  11. The difference between the synchronous speed and the actual rotor speed is called:
    • Motor speed
    • Slip speed
    • Actual speed
    • Field speed

  12. The difference between the dry bulb temperature and wet bulb temperature is called:
    • Dewpoint depression
    • Wet bulb depression
    • Dry bulb depression
    • Humidity

  13. A low side float valve maintains the level of refrigerant in:
    • Condenser
    • Evaporator
    • Baudelot cooler
    • Flooded evaporator

  14. Boiling point of R 600a is:
    • −33°C
    • −12°C
    • −77°C
    • −40°C

  15. RF remote control with a range of roughly:
    • 100 feet
    • 40 feet
    • 20 feet
    • 10 feet

  16. Bush bearings are usually made of:
    • Nickel
    • Bronze
    • Steel
    • Platinum

  17. The sediments which form as a coating on cooling coil will reduce the __________.
    • Temperature
    • Heat transfer efficiency
    • Suction pressure
    • Heat load on evaporator

  18. The extinguisher used for electric fire is:
    • Carbon tetrachloride extinguisher
    • Carbon dioxide extinguisher
    • Soda foam extinguisher
    • Methyl bromide extinguisher
    Question Error

  19. Cutting of sheet metal by two parallel cutting edge moving in opposite direction is termed as:
    • Drawing
    • Swaging
    • Shearing
    • Piercing

  20. Water is used as a refrigerant:
    • Vapour absorption cycle
    • Vapour compression cycle
    • Steam jet refrigeration
    • Air cycle
    Question Error

  21. The upcoming alternative refrigerant to be used in car air conditioning system is __________.
    • R 134a
    • R 1234ze
    • R 1234yf
    • R 764

  22. Comfort cooling ducts are commonly fabricated out of:
    • GI
    • Aluminium
    • FRP
    • All of these
    Question Error

  23. In saturated air:
    • DBT = WBT
    • WBT = DPT
    • DBT = DPT
    • All of these

  24. VRF stands for:
    • Varying Recirculated Flow
    • Variable Refrigerant Flow
    • Varying Refrigerant Functions
    • None of these

  25. The gap between the false ceiling and the main ceiling is referred as:
    • Supply air duct
    • Plenum
    • Return air duct
    • Diffuser

  26. During installation of split AC unit, what is the maximum vertical distance between indoor and outdoor units?
    • 20 feet
    • 30 feet
    • 15 feet
    • 40 feet

  27. Water pressure cut out switch is installed in:
    • Cooling tower line
    • Condenser water line
    • Chilled water line
    • Both "Condenser water line" and "Chilled water line"

  28. For leak testing, maximum test pressure for split AC system is:
    • 70 PSIG
    • 150 PSIG
    • 100 PSIG
    • 200 PSIG

  29. Cylindrical and needle roller bearings are commonly found in:
    • Fans
    • Rollerblades
    • Gearboxes
    • DC machines

  30. Following are the methods of food preservation:
    • Dehydration
    • Hydration
    • Canning
    • Both "Dehydration" and "Canning"

  31. A motor has 4 poles, its RPM is:
    • 1500
    • 3000
    • 750
    • 500

  32. Cooling performance test can only effectively done at ambient temperature above:
    • 60°F
    • 65°F
    • 70°F
    • 75°F

  33. If we use solar panels to run a car AC then the mileage of car will:
    • Increase
    • Decrease
    • Remain same as earlier
    • None of these

  34. The main working substance in air conditioning is __________.
    • Dry air
    • Moist air
    • Dry ice
    • Water vapour

  35. The temperature at which moisture condenses on a surface is called __________.
    • Grains of moisture
    • Wet bulb temperature
    • Dry bulb temperature
    • Dewpoint temperature

  36. Scaling:
    • Means attaching a scale to system pipes for the length measurement.
    • Is an instrument for measuring the length.
    • Deposition of a layer of chemicals inside a water carrying pipe in a heat exchanger.
    • None of these

  37. What is DDC in HVAC system?
    • Direct Decimal Classification
    • Direct Drive Control
    • Direct Current
    • Direct Digital Control

  38. Which valve allows fluid flow in only one direction?
    • Ball valve
    • Butterfly valve
    • Check valve
    • Shut-off valve

  39. Cylinder colour code for R 22 is:
    • Light green
    • Orange
    • Light grey
    • Light brown

  40. In a scroll compressor:
    • Both discharge and suction ports are located in the outer periphery
    • Both discharge and suction ports are located near the centre
    • The discharge port is in the centre and suction port is on the outer periphery
    • The suction port is in the centre and the discharge port is on the outer periphery

  41. Piercing valves are used to tap a line for:
    • Recovery
    • Testing
    • Charging
    • All of these

  42. Window and split air conditioning units are used __________ compressor motors.
    • CSR
    • RSIR
    • CSIR
    • Shaded pole

  43. Airflow quantities are measured in:
    • FPM
    • PSI
    • BTU
    • CFM

  44. Screwdrivers are classified according to:
    • Length
    • Size of working tip
    • Shape of working tip
    • All of these

  45. Compressor crankshaft seal prevents __________ from escaping out.
    • Air
    • Oil and Refrigerant
    • Refrigerant
    • Oil

  46. In a refrigeration cycle, the heat is rejected by refrigerant at:
    • Compressor
    • Evaporator
    • Expansion valve
    • Condenser

  47. For brazing most commonly used flux is:
    • Borax
    • Resin
    • NHU4
    • Carbonate chloride

  48. Single phase motor is __________.
    • Shaft starting
    • Self-starting
    • Not self-starting
    • None of these

  49. Liquid receiver in a vapour compression system is used in __________.
    • Suction line
    • Discharge line
    • Liquid line
    • Expansion line

  50. HEPA stands for:
    • High Energy Particulate Air
    • High-Efficiency Particulate Air
    • High Effective Pressurized Air
    • High Entry Particulate Air

  51. ADP represents:
    • Coil temperature
    • Coil pressure
    • Coil point
    • None of these

  52. GWP of R 134a refrigerant:
    • 1700
    • 1300
    • 800
    • 650

  53. Atmospheric pressure at sea level is:
    • 1.01325 bar
    • 14.7 PSI
    • 760000 Microns
    • All of these

  54. Following is an HC refrigerant:
    • R 600a
    • R 12
    • R 22
    • R 134a

  55. Capillary tube is used for __________.
    • Low capacity system
    • High capacity system
    • Medium capacity system
    • None of these

  56. What is the reason for poor condensation in Split AC?
    • Condenser fan motor failure
    • Sufficient airflow
    • Condenser tubes are nice
    • Condenser fin damage
    Question Error

  57. Which instrument is used for measuring humidity?
    • Hydrometer
    • Thermometer
    • Hygrometer
    • Anemometer

  58. ODP Value of HFC 134a:
    • 1
    • 3
    • 0
    • 2

  59. De-superheating takes place in __________.
    • Compressor
    • Discharge line
    • Condenser
    • Both "Discharge line" and "Condenser"

  60. The ratio of the sensible heat to the total heat is known as:
    • Sensible heat factor
    • ADP
    • Enthalpy
    • Relative humidity

  61. The compressor motor in a hermetically sealed compressor is cooled by:
    • Water
    • Air
    • Refrigerant
    • Nitrogen

  62. Float valves are used in:
    • Refrigerators
    • Large refrigeration systems
    • Package units
    • Split AC

  63. Velocity pressure is:
    • Difference between Static pressure and Air pressure
    • Difference between Total pressure and Static pressure
    • Difference between Air velocity and Air pressure
    • None of these

  64. The unit of Resistance is __________.
    • Ohm
    • Farad
    • Volt
    • Ampere

  65. The heart of the refrigeration system is __________.
    • Condenser
    • Evaporator
    • Liquid receiver
    • Compressor

  66. Which line in Psychrometric chart as obliquely inclined straight lines and uniformly spaced?
    • Relative humidity lines
    • Specific humidity lines
    • Enthalpy
    • Specific volume

  67. In star delta starter the main contactor is named as:
    • KM 1
    • KM 2
    • KM 3
    • K1T

  68. What is the purpose of adding dye in compressor lubricating oil to the Car AC system?
    • Identify the gas leak
    • Lubricate the engine
    • Adding performance
    • Improve efficiency

  69. The relationship between rotor speed ‘N’, frequency ‘f’ and no. of poles ‘P’ given by the relation:
    • N=120f/P
    • PN=120f
    • f=120N/P
    • N=120P/f

  70. The coil has to be rinsed after de-scaling till the pH level comes to:
    • 5 to 5.5
    • 6 to 6.5
    • 7 to 7.5
    • 8 to 8.5

  71. The voltmeter can be used in __________.
    • Series connection
    • Parallel connection
    • Combination of both series and parallel
    • None of these

  72. During sensible heating of moist air, specific humidity:
    • Increases
    • Decreases
    • Remains constant
    • None of these

  73. The fresh air or ventilation air is a must in any comfort air conditioning system. Its purposes are __________.
    • to provide oxygen
    • to remove carbon dioxide
    • to remove odours
    • All of these

  74. Refrigerant propane has the designation __________.
    • R 11
    • R 134a
    • R 290
    • R 12

  75. The expansion device used in central AC plant is:
    • AXV
    • TXV
    • Capillary tube
    • Solenoid valve

  76. The chemical name of refrigerant R 134a is __________.
    • Propane
    • Dichloro difluoro methane
    • Tetrafluoroethane
    • Monochlorodifluoroethane

  77. Bourdon tube is a __________.
    • Pressure measuring device
    • Volume measuring device
    • Density measuring device
    • Temperature measuring device

  78. Three TR is equivalent to __________ of cooling effect.
    • 5 kJ/s
    • 10.5 kW
    • 10 kJ/s
    • 7 kW

  79. Dry Bulb Temperature (DBT) is the actual temperature of __________.
    • Dry air
    • Dry ice
    • Water vapour
    • Moist air

  80. Tools used for making external threads is:
    • Taps
    • Die
    • Thread gauge
    • Drill

  81. Which one of the following is not a basic features of the Indian Constitution?
    • Parliamentary form of Government
    • Federal form of Government
    • Presidential form of Government
    • Independence of Judiciary

  82. The number of Fundamental Rights Constitution originally consists of:
    • 6
    • 8
    • 7
    • 9

  83. The first, Right to Information application submitted by Shahid Raza Burney to a police in:
    • Pune
    • Thane
    • Muzaffarnagar
    • Patna

  84. In which year National Rural Employment Guarantee Yojana (NREGY), scheme was renamed as MNREGA?
    • February, 2006
    • April, 2006
    • August, 2009
    • December 2009
    Question Error

  85. The CMS press, Kottayam, was established in 1821 by:
    • Dr. Herman Gundert
    • Rev. Benjamin Bailey
    • Kuriakkose Elias Chavara Achan
    • Anjelo Francis

  86. ‘Make Namboodhiri a human being’ was the slogan of:
    • Samathwa Samajam
    • Jathinasini Sabha
    • Kalliyanadayani Sabha
    • Yogakshema Sabha

  87. The movement that led to the formation of the first Public Service Commission in the state of Travancore was:
    • Guruvayoor Satyagraha
    • Civil Disobedience Movement
    • Nivarthana Agitation
    • Vaikom Satyagraha

  88. Which Patriot was the brain behind Malayali Memorial Petition submitted to Maharaja of Travancore?
    • G.P. Pillai
    • K. Kelappan
    • Dr. Palpu
    • Chempaka Raman Pillai

  89. Which is the paper edited by C. Krishnan to campaign vigorously against untouchability?
    • Kerala Kaumudi
    • Mitavadi
    • Desabhimani
    • Sujanandini

  90. ‘Ritumati’, the drama portrayed the cloistered life led by Namboothiri women, written by:
    • V.T. Bhattathiripad
    • M.P. Bhattathiripad
    • Kurur Nilakantan Namboothiripad
    • N. Krishna Pillai

  91. The freedom fighter belong to famous Palakkad Anakkara Vadaketh family:
    • Lalitha Prabhu
    • Parvathi Nenmani Mangalam
    • A.V. Kuttimalu Amma
    • Arya Pallam

  92. Who is the social reformer voiced against caste system and untouchability through the ‘Jathikummi’?
    • P.K. Chathan Master
    • Vagbhatananda
    • Sahodaran Ayyappan
    • Pandit K.P. Karuppan

  93. The Kerala leader attended Coconada (Kakinada) congress session in 1923 and enlisted congress support in his fight for social justice:
    • Dr. Ayyathan Gopalan
    • C. Krishnan
    • C.V. Kunjuraman
    • T.K. Madhavan

  94. ‘Ente Poorvakala Smaranakal’, the work written by the political leader:
    • A.K. Gopalan
    • A.K. Antony
    • V.T. Bhattathiripad
    • E.M.S. Namboothiripad

  95. In which year G. Sankara Kurup got the Bharatiya Gnanapidham Award?
    • 1968
    • 1966
    • 1955
    • 1976

  96. Who is the present CEO of Rajya Sabha T.V.?
    • Gurdeep Singh Sappal
    • Shashi Sekhar Vempati
    • P.J. Kurian
    • M. Venkaiah Naidu

  97. Who is the winner of US open badminton Championship Men’s Single held at California in 24th July 2017?
    • H.S. Pranoy
    • Parupalli Kashyap
    • Kidambi Srikanth
    • Sai Praneeth

  98. Who is the director of controversial Bollywood film ‘Indu Sarkar’?
    • Tigmanshu Dhulia
    • Madhur Bhandarkar
    • Sayed Ahamed Afzal
    • Mohit Marwah

  99. Who is the present Chairman of NITI Aayog?
    • Dr. Rajiv Kumar
    • Aravind Panagaria
    • Amitabh Kanth
    • Sri. Narendra Modi

  100. ‘Freedom From Waste’ campaign launched by:
    • Suchithwa Mission
    • Swachh Bharath
    • Life Mission
    • Haritha Kerala Mission
    Question Error

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