Q. The ratio of emissive power of a body to the emissive power of a perfectly black body is called emissivity.

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Q. The thermostatic expansion valve operates on the changes in the

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Q. In a vapour compression system, the condition of refrigerant before entering the expansion or throttle valve is

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Q. The freezing point of R-12 is

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Q. The refrigerant supplied to a compressor must be

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Q. The unit of thermal diffusivity is

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Q. The superheated vapour region, in a pressure enthalpy chart, is represented by the space

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Q. The minimum temperature to which water can be cooled in a cooling tower is

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Q. The index which corelates the combined effects of air temperature, relative humidity and air velocity on the human body, is known as

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Q. The ratio of Nusselt number and the product of Reynold's number and Prandtl number is equal to

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Q. The alignment circle is marked on the psychrometric chart at

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Q. The operating temperature of a cold storage is - 2° C. The heat leakage from the surrounding is 30 kW for the ambient temperature of 40° C. The actual C.O.P. of refrigeration plant used is one fourth that of ideal plant working between the same temperatures. The power required to drive the plant is

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Q. In chemical dehumidification process,

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Q. A one tonne refrigerating machine means that

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Q. The air cooling system mostly used in transport type aircrafts is

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Q. The critical thickness of insulation is the ratio of thermal conductivity of the insulating material (k) to the heat transfer coefficient at the outer surface of the insulation (h0).

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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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