Q. Fourier's law of heat conduction is (where Q = Amount of heat flow through the body in unit time, A = Surface area of heat flow, taken at right angles to the direction of heat flow, dT = Temperature difference on the two faces of the body, dx = Thickness of the body, through which the heat flows, taken along the direction of heat flow, and k = Thermal conductivity of the body)

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Q. The heat transfer by conduction through a thick sphere is same as through a thick cylinder.

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Q. The humidity ratio or specific humidity is the mass of water vapour present in

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Q. The formation of frost on cooling coils in a refrigerator

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Q. The by-pass factor for a cooling coil

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Q. The difference between dry bulb temperature and wet bulb temperature, is called

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Q. Defrosting of a refrigerator may be done by stopping the compressor for a short period.

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Q. In aqua-ammonia and Lithium-bromide water absorption refrigeration systems, the refrigerants are respectively

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Q. As relative humidity decreases, the dew point temperature will be __________ wet bulb temperature.

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Q. The process of heat transfer from a hot body to a cold body, in a straight line, without affecting the intervening medium, is called radiation.

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Q. Reynolds number (RN) is given by (where h = Film coefficient, l = Linear dimension, V = Velocity of fluid, k = Thermal conductivity, t = Temperature, ρ = Density of fluid, cp = Specific heat at constant pressure, and μ = Coefficient of absolute viscosity)

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Q. The optimum effective temperature for human comfort is

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Q. The wet bulb temperature lines, on the psychrometric chart, are curved lines.

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Q. The sensible heat factor during cooling and dehumidification process is given by (where h1 = Enthalpy of air entering the cooling coil, h2 = Enthalpy of air leaving the cooling coil, and hA = Enthalpy of air at the end of dehumidification process)

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Q. Thermal diffusivity is a

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Q. The condition of refrigerant after leaving the compressor and before entering the condenser is superheated vapour.

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Q. The total radiation from a black body per second per unit area is __________ fourth power of the absolute temperature. This statement is known as Stefan-Boltzmann law.

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Q. In a psychrometric process, the sensible heat added is 30 kJ/s and the latent heat added is 20 kJ/s. The sensible heat factor for the process will be

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Q. The amount of radiation mainly depends upon the

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Q. For ammonia refrigerating systems, the tubes of a shell and tube condenser are made of

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