Q. A fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter 'd'. For a fixed mass flow rate, the tube side heat transfer co-efficient for turbulent flow conditions is proportional to

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Q. Prandtl and Reynolds analogy are same, when Prandtl number is

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Q. Heat transfer occurs by natural convection because change in temperature causes difference in

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Q. The ratio of kinematic viscosity to thermal diffusivity is called the __________ number.

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Q. Baffles are provided in heat exchangers to increase the

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Q. 200 kg of solids (on dry basis) is subjected to a drying process for a period of 5000 seconds. The drying occurs in the constant rate period with the drying rate as, Nc = 0.5 x 10⁻³ kg/m².s. The initial moisture content of the solid is 0.2 kg moisture/kg dry solid. The interfacial area available for drying is 4 m²/1000 kg of dry solid. The moisture content at the end of the drying period is (in kg moisture/kg dry solid)

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Q. In case of a vertical tube evaporator, with increase in the liquor level, the

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Q. The ratio of total radiating power to the absorptivity of the body depends upon the __________ as per Kirchoffs law.

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Q. For gases, the thermal conductivity increases with temperature rise. For liquids, with increase in concentration, its thermal conductivity generally

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Q. Mechanical recompression evaporation is used in the production of

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Q. A measure of the extent to which viscous heating is important relative to the heat flow resulting from the impressed temperature difference is represented by the __________ number.

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Q. Out of 100 kcal/second of incident radiant energy on the surface of a thermally transparent body, 300 kcal/second is reflected back. If the transmissivity of the body is 0.25, the emissivity of the surface will be

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Q. The purpose of providing a 'catchall' in the vapor line of an evaporator is to

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Q. What is the thermal conductivity of a perfect heat insulator ?

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Q. In a single effect evaporator, the economy is

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Q. LMTD correction factor which is to be applied for a cross-flow heat exchanger increases with increase in the number of shell passes. Its value for a single pass cross flow heat exchanger is

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Q. Which of the following is not concerned with the heat transfer?

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Q. Latent heat absorbed by 1 lb of water at 212°F, when it is changed to steam at 212°F, may be around __________ BTU.

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Q. In counter flow compared to parallel flow,

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Q. The thermal radiative flux from a surface of emissivity = 0.4 is 22.68 kW/m². The approximate surface temperature (K) is (Stefan-Boltzman constant = 5.67x10⁻⁸ W/m².K⁴)

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