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Mechanical Engineering :: Refrigeration and Air Conditioning

  1. The bank of tubes at the back of domestic refrigerator is

  2. A.

     Condenser tubes

    B.

     Evaporator tubes

    C.

     Refrigerant cooling tubes

    D.

     Capillary tubes


  3. The C.O.P. of a Carnot refrigerator in winter will be _________ as compared to C.O.P. in summer.

  4. A.

     Same

    B.

     Lower

    C.

     Higher

    D.

     None of these


  5. Carbon dioxide is

  6. A.

     Colourless

    B.

     Odourless

    C.

     Non-flammable

    D.

     All of these


  7. On the pressure-enthalpy diagram, condensation and desuperheating is represented by a horizontal line because the process

  8. A.

     Involves no change in volume

    B.

     Takes place at constant temperature

    C.

     Takes place at constant entropy

    D.

     Takes place at constant pressure


  9. The humidification process, on the psychrometric chart is shown by

  10. A.

     Horizontal line

    B.

     Vertical line

    C.

     Inclined line

    D.

     Curved line


  11. For better C.O.P of refrigerator, the pressure range corresponding to temperature in evaporator and condenser must be

  12. A.

     Small

    B.

     High

    C.

     Equal

    D.

     Anything


  13. Choose the correct statement

  14. A.

     A refrigerant should have low latent heat

    B.

     If operating temperature of system is low, then refrigerant with low boiling point should be used

    C.

     Pre-cooling and sub-cooling bf refrigerant are same

    D.

     Superheat and sensible heat of a refrigerant are same


  15. The C.O.P. of a heat pump working on a reversed Carnot cycle is

  16. A.

     T₁/(T₂ - T₁)

    B.

     (T₂ - T₁)/T₁

    C.

     (T₁ - T₂)/T₁

    D.

     T₂/(T₂ - T₁)


  17. Critical pressure of a liquid is the pressure

  18. A.

     Above which liquid will remain liquid

    B.

     Above which liquid becomes gas

    C.

     Above which liquid becomes vapour

    D.

     Above which liquid becomes solid


  19. In a pressure enthalpy chart, the space to the left of the saturated liquid line represents

  20. A.

     Wet vapour region

    B.

     Superheated vapour region

    C.

     Sub-cooled liquid region

    D.

     None of these