Q. Air conditioning means

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Q. The emissivity for a black body is

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Q. Which of the following would lead to a reduction in thermal resistance?

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Q. The ratio of the thickness of thermal boundary layer to the thickness of hydrodynamic boundary layer is equal to (Prandtl number)n, where n is equal to

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Q. The curved lines on a psychrometric chart indicates

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Q. During humidification process, __________ increases.

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Q. A pressure gauge on the discharge side of a refrigerant compressor reads too high. The reasons will be

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Q. The counter-current flow heat exchanger can transfer __________ heat than parallel flow heat exchanger.

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Q. The freon group of refrigerants are

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Q. The centrifugal compressors are generally used for refrigerants that require

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Q. The water, alcohol and ammonia have same refrigerating effect at different altitudes.

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Q. The automobile radiator is a heat exchanger of

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Q. In mechanical refrigeration system, the refrigerant occurs as liquid between condenser and expansion valve.

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Q. A heat pump working on a reversed Carnot cycle has a C.O.P. of 5. It works as a refrigerator taking 1 kW of work input. The refrigerating effect will be

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Q. For evaporators and condensers, for the given conditions, the logarithmic mean temperature difference (tm) for parallel flow is __________ that for counter flow.

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Q. A vapour absorption refrigerator uses __________ as a refrigerant.

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Q. Thermal conductivity of air increases with rise in temperature.

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Q. The material of pipe lines for a system using ammonia as a refrigerant should be copper.

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Q. The wave length corresponding to the maximum energy is inversely proportional to the absolute temperature. This statement is called Planck's law.

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Q. The sensible heat gain is due to the __________ difference between the fresh air and the air in space.

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