Q. Convective heat transfer co-efficient in case of fluid flowing in tubes is not affected by the tube length/diameter ratio, if the flow is in the __________ zone.

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Q. The actual temperature drop across the heating surface in an evaporator depends on the

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Q. Which of the following is not used as a medium for high temperature heating ?

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Q. Presence of a non-condensing gas in a condensing vapour

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Q. The average heat transfer co-efficient for laminar film condensation on vertical surface is inversely proportional to (where, ΔT = Temperature drop across condensate film )

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Q. Bulk of the convective heat transfer resistance from a hot tube surface to the fluid flowing in it, is

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Q. Which of the following is concerned with both heat and mass transfer ?

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Q. A backward feed multiple effect evaporator is better than forward feed for concentrating cold feed, because it provides

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Q. A 10 cm diameter steam pipe, carrying steam at 180°C, is covered with an insulation (conductivity = 0.6 W/m.°C). It losses heat to the surroundings at 30°C. Assume a heat transfer co-efficient of 0.8 W/m².°C for heat transfer from surface to the surroundings. Neglect wall resistance of the pipe and film resistance of steam. If the insulation thickness is 2 cms, the rate of heat loss from this insulated pipe will be

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Q. Fouling factor

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Q. In case of vertical tube evaporator, with increase in liquor level, the overall heat transfer co-efficient

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Q. The steam ejector is used to

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Q. For shell and tube heat exchanger, with increasing heat transfer area, the purchased cost per unit heat transfer area

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Q. The thermal efficiency of a reversible heat engine operating between two given thermal reservoirs is 0.4. The device is used either as a refrigerator or as a heat pump between the same reservoirs. Then the coefficient of performance as a refrigerator (COP)R and the co-efficient of performance as a heat pump (COP)HP are

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Q. Crystal size in a continuous crystalliser depends upon the

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Q. Heat waves

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Q. Air is best heated with steam in a heat exchanger of

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Q. Which of the following is generally considered as opaque surface towards radiations?

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Q. Black liquor generated during paper manufacture is concentrated in a

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Q. When vaporisation takes place directly at the heating surface, it is called

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