A/C Mechanic Kerala Tourism Development Corporation KTDC 112/2017 Answer Key 132/2017

air coditioner

Post : A/C Mechanic
Department : Kerala Tourism Development Corporation KTDC
Category Code : 112/17
Qualification : SSLC + NTCT MRCA or A/C mechanic
Question Paper Code : 132/17
Date of Test : 13-11-2017

If you find mistakes, comment below



  1. What thickness of metal sheets are called as plates?
    • Above 3 mm
    • Above 5 mm
    • Above 7 mm
    • Above 10 mm

  2. What gases are used for the application underwater gas cutting of steel?
    • Oxygen-coal
    • Oxygen-LPG
    • Oxygen-Hydrogen
    • Oxygen-Acetylene

  3. In which gas welding technique the blow pipe and filler rod angles are 50 and 40 respectively with the welding line?
    • Rightward
    • Leftward
    • Rightward and Leftward
    • All of these

  4. Soldering & Brazing are the examples of non-fusion welding
    • Fusion welding
    • Non-fusion welding
    • Pressure welding
    • Forge welding

  5. Which type of artificial respiration method must not be used for the victim has injuries to the chest and belly?
    • Mouth to mouth method
    • Schafer’s method
    • Nelson’s arm – lift back-pressure method
    • Mouth to nose method

  6. Metering device used in car air-conditioner
    • Electronic expansion valve
    • Automatic expansion valve
    • Capillary tube
    • Thermostatic expansion valve

  7. VRV stands for _________
    • Varying Recirculated Volume
    • Variable Refrigerant Volume
    • Varying Refrigerant Volume
    • None of these

  8. The package AC comes in capacity _________.
    • less than 2 TR
    • between 2 to 4 TR
    • between 5 to 15 TR
    • more than 25 TR

  9. Rawl plug tool is used for making _________.
    • Bending
    • Grinding
    • Cutting
    • Hole

  10. Commercial reciprocating compressor lubricated by
    • Forced feed
    • Splash lubrication
    • Machine lubrication
    • None of these

  11. Centrifugal switch disconnected after the rotor has reached _________ of the rated speed.
    • 50 to 55%
    • 55 to 60%
    • 70 to 75%
    • 75 to 80%

  12. Why is three phase induction motor self starting?
    • phase angle difference 60
    • phase angle difference 180
    • phase angle difference 90
    • phase angle difference 120

  13. Standard atmospheric pressure is
    • 1.0332 kg f/sq.cm.
    • 1.332 kg f/sq.cm.
    • 2.0332 kg f/sq.cm.
    • All these

  14. Chemical formulae of R-600 a
    • C5H12
    • C2H6
    • C3H8
    • C4H10

  15. What is general chemical formula for finding Refrigerant Numbering?
    • CmHnClpFq and n + p + q = 2p + 2
    • CmHnClpFq and n + p + q = 2m + 2
    • CmHnClpFq and n + p + q = 2n + 2
    • CmHnClpFq and n + p + q = 2q + 2

  16. What is the colour code of Refrigerant 410 A?
    • Rose
    • Orange
    • Chocolate Brown
    • Coral Red

  17. The various methods of duct design are _________
    • Equal friction method
    • Velocity reduction method
    • Static regain method
    • All of these

  18. ‘HEPA’ stands for _________.
    • High Energy Particulate Air
    • High Efficiency Particulate Air
    • High Entry Particulate Air
    • Highly Effective Pressurized Air

  19. As the engine speed decreases, the cooling capacity of the car AC system _________.
    • increases
    • remains unchanged
    • decreases
    • may increase or decrease depending on number of persons traveling in car

  20. Refrigerant 407 C is combination of _________.
    • R-290 & R-1270
    • R-600a & R-134a
    • R-125, R-600 & R-134a
    • R-32, R-125 & R-134a

  21. What is temperature of Neutral flame in Oxy-Acetylene Brazing set?
    • 2200 C
    • 3200 C
    • 4200 C
    • 5200 C

  22. 1 micron = _________ millimetre of Hg.
    • 1/100
    • 1/1000
    • 1/10000
    • 1/10

  23. Azeotropic Mixtures are designed by _________ series.
    • 500
    • 400
    • 700
    • 600

  24. How are the reciprocating compressor classified depending on working?
    • Vertical & Horizontal
    • Single & Double acting
    • Open type & Semi sealed
    • Semi & Hermetically sealed

  25. GWP of R-11 is
    • 8500
    • 5400
    • 4500
    • 1800

  26. How much air is normally required for the working of air-cooled condenser per ton of refrigeration?
    • 50 to 55 cu.m/min.
    • 30 to 35 cu.m/min.
    • 20 to 25 cu.m/min.
    • 60 to 65 cu.m/min.

  27. The thermistors are _________
    • pressure type temperature sensors
    • bellow type temperature sensors
    • resistance type temperature sensors
    • all of these

  28. What are the examples of non-fusion welding?
    • Arc welding
    • Oxy-Acetylene welding
    • Soldering
    • None of these

  29. Alternative refrigerant of R-22
    • R-401 A
    • R-410 A
    • R-500
    • R-507

  30. Voltage rating of starting capacitor used in ACs
    • 410 V
    • 230 V
    • 440 V
    • 110 V

  31. 50 F is _________
    • 12.5 C
    • 5 C
    • 7.5 C
    • 10 C

  32. What is a Rectifier?
    • DC to AC converter
    • AC to DC converter
    • Both 'DC to AC converter' and 'AC to DC converter' possible
    • None of these

  33. What is the voltage required for LED?
    • 1.2 – 2.5 V
    • 2.2 – 3.5 V
    • 3.2 – 4.5 V
    • 4.2 – 5.5 V

  34. How many diodes are there in a bridge rectifier?
    • 2
    • 3
    • 4
    • 6

  35. Which is the semi-conductor device with three terminals and used for amplifying electric and electronic signals?
    • Diode
    • Transistor
    • Capacitor
    • Zener diode

  36. What type of relay is used in RSIR?
    • Voltage type relay
    • Hotwire relay
    • PTC relay
    • Current coil relay

  37. The vapour pressure of refrigerant should be
    • lower than atmospheric pressure
    • higher than atmospheric pressure
    • equal to atmospheric pressure
    • none of these

  38. One of the purposes of sub-cooling the liquid refrigerant is to
    • reduce compressor over-heating
    • reduce compressor discharge temperature
    • increase cooling effect
    • ensure that only liquid and not the vapour enters the expansion valve

  39. At lower temperatures and pressures, the latent heat of vaporization of a refrigerant
    • decreases
    • increases
    • remains same
    • depends on other factors

  40. For ammonia refrigerating systems, the tubes of a shell and tube condenser are made up of
    • Copper
    • Steel
    • Aluminium
    • Brass

  41. The higher temperature in vapour compression cycle occurs at __________.
    • Receiver
    • Expansion valve
    • Condenser discharge
    • Compressor discharge

  42. Latent heat of vaporization at 5 F (Btu/lb) of R-134 a is __________.
    • 66.2
    • 99.2
    • 103.3
    • 89.3

  43. The weight of HC charged to the system for drop in conversion from CFC 12 to HC is
    • 120%
    • 100%
    • 60%
    • 40%

  44. Most of the refrigerants including CFCs, HCFcs, HFCs and HC blend are __________.
    • Non-toxic
    • Corrosive
    • High density
    • Non-flammable

  45. A refrigerant recovery unit needs the filter drier change, approximately after __________.
    • 50 to 60 hours of operation
    • 100 hours of operation
    • every 24 hours
    • every time before recover refrigerants

  46. The clearance between rotor and stator varies according to the __________.
    • Coil of the motor
    • Air passage
    • Cable size
    • Size of the motor

  47. The ball bearing of electrical motor are lubricated by __________.
    • Oil
    • Grease
    • Air
    • Water

  48. Which causes clogging at the expansion valve?
    • Oil
    • Dust particles
    • Moisture
    • Impurities

  49. The reason for the thermostat switch to become defective is __________.
    • Moisture in the system
    • Lack of lubrication oil to compressor
    • Carbon formation of contact points
    • OLP is not functioning

  50. High pressure cut off is used to __________
    • cut off power supply to condenser fan motor if pressure increases beyond the preset value.
    • cut off power supply to compressor motor if pressure increases beyond the preset value.
    • cut off power supply to evaporator fan motor if pressure increases beyond the preset value.
    • None of these

  51. Air velocity is measured by __________.
    • Tachometer
    • Anemometer
    • Hydrometer
    • Thermometer

  52. The solenoid valve operated by __________.
    • Hand operated
    • Oil pressure operated
    • Gas pressure operated
    • Electrically operated

  53. Brine solution circulation pump consists of __________.
    • Piston type
    • Gear type
    • Rotary type
    • Rotating vane type impeller

  54. A water cooler is having 4 kg (weight) quantity of R-12, if you retrofit with HFC for the same machine. How much quantity is weight of 134a you will charge?
    • 3.8 kgs.
    • 3.2 kgs.
    • 2.4 kgs.
    • 1.6 kgs.

  55. Ice cream storage plant thermostat thermal bulb is located ________.
    • near suction line
    • at liquid line
    • inside the storage compartment
    • in brine solution

  56. The function of duct in air conditioning unit is _________
    • Air cooling
    • Air cleaning
    • Air drying
    • Air distributing

  57. A cooling tower’s warm water inlet temperature is 44 C, sump water outlet temperature is 32 C, surrounding air wet bulb temperature is 24 C. Find out the efficiency of the cooling tower in percentage.
    • 60%
    • 40%
    • 80%
    • 75%

  58. The cut-in and cut-out set pressure difference is called
    • set pressure
    • differential pressure
    • cut-out pressure
    • cut-in pressure

  59. Compressor motor protected by the ___________.
    • low pressure switch
    • overload protector
    • high pressure switch
    • temperature control

  60. The purified, conditioned air improves the ___________.
    • Breathing of human
    • Cleaning of AC room
    • Performance of the system
    • Quality of the air filters

  61. Which instrument is used to measure relative humidity?
    • Hydrometer
    • Psychrometer
    • Hygrometer
    • Thermometer

  62. What is the purity of dry nitrogen for flushing?
    • 10 ppm
    • 15 ppm
    • 3 ppm
    • 8 ppm

  63. By using which valve in the charging line, the refrigerant can be recovered?
    • Service valve
    • Hand shut off valve
    • Piercing valve
    • Double stage regulator

  64. The relationship between rotor speed ‘N’, frequency ‘f’ and number of poles ‘p’ is given by relation
    • N = 120 f/p
    • PN = 120/p
    • f = 120 N/p
    • N = 120 p/f

  65. A oil separator is necessary in discharge line to return the oil to the compressor in case of ______
    • R-290
    • R-717
    • R-12
    • R-600a

  66. An evaporative condenser is a _________.
    • Air cooled condenser
    • Water cooled condenser
    • Both air and water cooled at the same time
    • None of these

  67. Approach of a cooling tower is defined as the
    • difference of dry bulb temperature of surrounding air and temperature of water leaving the cooling tower.
    • difference of temperature of water leaving the cooling tower and wet bulb temperature of surrounding air.
    • difference of temperature of water leaving the cooling tower and temperature of water entering the cooling tower.
    • None of these

  68. In a induced draft cooling tower, the fan is fixed at the _________.
    • top of the cooling tower
    • middle of the cooling tower
    • bottom of the cooling tower
    • any location of the cooling tower

  69. A thermostatic expansion valve is based on the principle of maintaining a constant degree of superheat at the _________.
    • discharge of compressor
    • exit of the condenser
    • exit of capillary tube
    • exit of evaporator

  70. The eliminators at the air washers avoid the
    • Air flow
    • Water particles in the air
    • Water flow
    • Dehumidification

  71. External equalizer is used with _________
    • AEV
    • TEV
    • High side flat valve
    • Low side flat valve

  72. Normally pressure relief valves are mounted on _________ in a refrigeration plant.
    • compressor
    • receiver
    • condenser
    • evaporator

  73. The best refrigerant is one for which _________.
    • ODP = 1
    • ODP = 0.5
    • ODP = 0.75
    • ODP = 0

  74. Relative COP = _________
    • Actual COP / Theoretical COP
    • Theoretical COP / Actual COP
    • Actual COP · Theoretical COP
    • None of these

  75. The refrigerant after condensation process is cooled below the saturation temperature before throttling. Such a process is called
    • Sub-cooling
    • Super-cooling
    • Normal cooling
    • None of these

  76. On P-H diagram, the isentropic compression process is represented by an
    • Inclined line
    • Vertical line
    • Horizontal line
    • Curved line

  77. The super-heating in a refrigeration cycle
    • Does not alter COP
    • Increase COP
    • Decrease COP
    • None of these

  78. How many numbers of orbits in the orbiting scroll of scroll compression process?
    • Three
    • Four
    • Two
    • One

  79. Most air cooled condensers are designed to operate with a temperature difference of
    • 6 C
    • 9 C
    • 14 C
    • 24 C

  80. The centrifugal compressor are generally used for refrigerants that require
    • small displacements and low condensing pressure.
    • large displacements and high condensing pressure.
    • small displacements and high condensing pressure.
    • large displacements and low condensing pressure.

  81. Eastern most point of India is ___________
    • Indira Point
    • Cape Comerine
    • Indira Col
    • Kibithu

  82. ___________ is the only Indian State through which the Indus flows.
    • Jammu Kashmir
    • Gujarat
    • Rajasthan
    • Haryana

  83. The coldest place in India is ___________.
    • Drass Valley
    • Shimla
    • Kashmir
    • Kodaikanal

  84. North-east monsoon is commonly known as
    • Graphic rainfall
    • October heat
    • Cherri Blossom
    • Mango shower

  85. Red colour of the ‘red soil’ is due to the high concentration of ___________.
    • Calcium oxide
    • Aluminium oxide
    • Iron oxide
    • Sodium chloride

  86. Egg bowl of India is ___________.
    • Kerala
    • Assam
    • Andhra Pradesh
    • Arunachal Pradesh

  87. Who is the Father of Indus Economics?
    • Dadabhai Naoroji
    • M. Viswesarayya
    • Jawaharlal Nehru
    • Sardar Patel

  88. First Five Year Plan gave priority to ___________
    • Poverty Alleviation
    • Industrialisation
    • Agricultural Development
    • Reducing Unemployment

  89. The first session of Swaraj Party was held at
    • Delhi
    • Allahabad
    • Lahore
    • Calcutta

  90. Ancient University named ‘Kandallursala’ situated in
    • Wyanad
    • Alappuzha
    • Thiruvananthapuram
    • Kollam

  91. The first floating ATM in Kerala is started in
    • Ernakulum
    • Thiruvananthapuram
    • Thrissur
    • Calicut

  92. Almost 68% of the total area of Kerala is ___________ soil group.
    • laterite
    • red
    • black
    • alluvial

  93. Which river in Kerala is known as ‘Baris’ in ancient days?
    • Pamba
    • Bharatapuzha
    • Periyar
    • Chandragiri

  94. Who is known as ‘Father of Modern Kerala Renaissance’?
    • Sri Narayana Guru
    • Chattambi Swamikal
    • Ayyankali
    • Vagbhadananda

  95. Who called Ayyankali as ‘Pulayaraja’?
    • Jawaharlal Nehru
    • Indira Gandhi
    • Mahatma Gandhi
    • E.K. Nayanar

  96. Who is the returning officer for the election to Vice President of India?
    • Attorney General of India
    • Chief Election Commissioner
    • Secretary Lok Sabha / Rajya Sabha
    • Chief Justice of India

  97. World Athletic meet 2017 take place at
    • London
    • Tokyo
    • Helsinki
    • Rio-de-Janeiro

  98. Who is the French President?
    • Tony Blair
    • Emmanuel Mucro
    • Nawab Sharif
    • Samuel Mucro

  99. In which year Olympics will take place in Los Angeles for the third time?
    • 2024
    • 2028
    • 2020
    • 2027

  100. Who is the Vice President of India?
    • Dr. Hameed Ansari
    • Dr. Pranab Mukherjee
    • Venkaiyya Naidu
    • Ramnath Kovind

%

Post a Comment

1 Comments

  1. In question number 67 approach of cooling tower is water leaving the coling tower and wet bulb temperature of surround air that is correct option B is correct option C is incorrect

    ReplyDelete