LPSC Refrigeration & Air Conditioning Mechanic Paper 2017
Liquid Propulsion Systems Center released a Recruitment Notification 2023 to recruit the 26 Technician posts. In this Refrigeration & Air conditioning Mechanic vacancy also available. You may apply on or before 30th May 2023. Here, we are providing the previous year question paper for your preparation.
| Sr. No. | Questions |
| 1 | Refrigerant used should be such that its normal boiling point is
(a) Greater than the temperature required (b) Less than the temperature required (c) Equal to the temperature required (d) None of these |
| 2 | Pressure of refrigerant in the evaporator should be
(a) Equal to the atmospheric pressure (b) Less than the atmospheric pressure (c) Greater than the atmospheric pressure (d) None of these |
| 3 | Primary refrigerant is one which is sensibly
(a) Heated in the evaporator (b) Cooled in the evaporator (c) Neither heated in evaporator nor cooled in condenser (d) None of these |
| 4 | Secondary refrigerant is one which is
(a) Cooled by the waer (b) Cooled by the air (c) Cooled by the primary refrigerant (d) None of these |
| 5 | Of the following, which can act as a primary, secondary as well as a tertiary refrigerant
(a) Water (b) Ammonia (c) Freon-22 (d) None of these |
| 6 | Which is the primary refrigerant in central air conditioning plant
(a) Air (b) Water (c) Freon-22 (d) None of these |
| 7 | Capillary tube is the expansion valve used in refrigeration and Air conditioning units of cooling capacity of ranges
(a) <3 tons (b) >3 tons (c) <10 tons (d) None of these |
| 8 | Automatic expansion valve is used to maintain
(a) Constant temperature (b) Constant pressure (c) Constant volume (d) None of these |
| 9 | Expansion process in the expansion valve is
(a) Free expansion (b) Throttling (c) Isotropic (d) None of these |
| 10 | Thermostatic expansion valve is located in between the
(a) Compressor and condenser (b) Condenser and evaporator (c) Evaporator and the compressor (d) None of these |
| 11 | Evaporators with finned tubes are used in a
(a) Window air conditioner (b) Fridge (c) Water cooler (d) None of these |
| 12 | Where is the evaporator in a refrigeration plant fitted?
(a) Before the condenser (b) After the condenser (c) After the compressor (d) None of these |
| 13 | Condenser in a refrigeration system decreases
(a) Pressure only (b) Temperature only (c) Temperature and pressure (d) None of these |
| 14 | Water cooled condensers are used when tons of refrigeration is
(a) <3 (b) <50 (c) > 100 (d) None of these |
| 15 | Heat lost in the condenser is due
(a) Decrease in the degree of super heat (b) Decrease in degree of super heat+ latent heat+ increase of degree of sub-cooling (c) Decrease in the degree of sub cooling (d) None of these |
| 16 | Reciprocating compressor is used when pressure difference between condenser and evaporator is
(a) > 1.5 bars (b) < 1.5 bars (c) > 3.5 bars (d) None of these |
| 17 | Centrifugal compressor is used when pressure difference between condenser and evaporator is
(a) > 1.5 bars (b) < 1.5 bars (c) > 3.5 bars (d) None of these |
| 18 | When do we need dual compressor in a refrigeration unit?
(a) When temperature to be achieved is around – 50 degree Celsius (b) When temperature to be achieved is around 5 degree Celsius (c) When temperature to be achieved is around -5 degree Celsius (d) None of the above |
| 19 | Ammonia compressors are always
(a) Water cooled (b) Air cooled (c) Water as well as air cooled (d) None of these |
| 20 | Degree of super heat is associated with
(a) Solids (b) Liquids (c) Vapors (d) None of these |
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