Home / Mechanical Engineering / Heat Transfer,Refrigeration and Air Conditioning :: Section 6

Mechanical Engineering :: Heat Transfer,Refrigeration and Air Conditioning

  1. If the condenser temperature is kept constant, the coefficient of performance of a refrigeration cycle increases with the increase in evaporator temperature.

  2. A.
    Yes
    B.
    No

  3. The process of heat transfer from one particle of the fluid to another by the actual movement of the fluid particles caused by some mechanical means, is known as

  4. A.
    conduction
    B.
    free convection
    C.
    forced convection
    D.
    radiation

  5. When α is absorptivity, ρ is reflectivity and τ is transmittivity, then for a diathermanous body,

  6. A.
    α = 1, ρ = 0 and τ = 0
    B.
    α = 0, ρ = 1 and τ = 0
    C.
    α = 0, ρ = 0 and τ = 1
    D.
    α + ρ = 1 and τ = 0

  7. When there is an addition of water vapour to the air of enclosed space, a gain in __________ is said to occur.

  8. A.
    sensible heat
    B.
    latent heat

  9. The relative humidity __________ as air gets drier.

  10. A.
    increases
    B.
    decreases

  11. The central air conditioning system has __________ overall efficiency as compared to individual systems.

  12. A.
    same
    B.
    lower
    C.
    higher

  13. The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as

  14. A.
    Wien's law
    B.
    Stefan's law
    C.
    Kirchhoff's law
    D.
    Planck's law

  15. An ordinary passenger aircraft requires a cooling system of capacity.

  16. A.
    2 TR
    B.
    4 TR
    C.
    8 TR
    D.
    10 TR

  17. In air-conditioning of aeroplanes, using air as a refrigerant, the cycle used is

  18. A.
    reversed Carnot cycle
    B.
    reversed Joule cycle
    C.
    reversed Brayton cycle
    D.
    reversed Otto cycle

  19. The thermal diffusivity for solids is generally less than those for liquids and gases.

  20. A.
    True
    B.
    False