Q. The heat transfer by conduction through a thick cylinder(Q) is given by (where T1 = Higher temperature, T2 = Lower temperature, r1 = Inside radius, r2 = Outside radius, l = Length of cylinder, and k = Thermal conductivity)

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Q. The heat is transferred by conduction, convection and radiation in

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Q. A thermostatic expansion valve in a refrigeration system

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Q. The temperature rise, between the condenser outlet and expansion valve in ammonia vapour compression system, should be as low as possible.

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Q. The ratio of the actual mass of water vapour in a unit mass of dry air to the mass of water vapour in the same mass of dry air when it is saturated at the same temperature and pressure, is called

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Q. The __________ point of ammonia is -77.7°C.

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Q. Sulphur dioxide has the lowest boiling point.

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Q. For a given dry bulb temperature, as the relative humidity __________ the wet bulb temperature will increase.

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Q. The lowest thermal diffusivity is of

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Q. A low wet bulb temperature indicates very __________ humidity.

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Q. In counter-current flow heat exchanger, the logarithmic temperature difference between the fluids is __________ as compared to parallel flow heat exchanger.

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Q. Environmental protection agencies advice against the use of chloro-fluoro-carbon refrigerants since

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Q. When the lower temperature of a refrigerating machine is fixed, then the coefficient of performance can be improved by

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Q. The refrigerant carbon dioxide is not widely used because of its __________ power require ments per tonne of refrigeration and high operating pressures.

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Q. The by-pass factor of a cooling coil decreases with

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Q. For unsaturated air, the dew point temperature is __________ wet bulb temperature.

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Q. During dehumidification process, __________ remains constant.

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Q. Pressure of water vapour is given by

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Q. The value of the wave length for maximum emissive power is given by

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Q. Emissivity of a body will be equal to its absorptivity at all temperatures.

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