Q. Which of the following has the lowest overall heat transfer co-efficient ?

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Q. Low thermal conductivity of heat insulating materials is due to its

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Q. The most conducive surface for dropwise condensation to occur is the __________ surface.

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Q. In an interphase heat transfer process, the equilibrium state corresponds to equality of temperature in the two phases, while the condition for equilibrium in an interphase mass transfer process is equality of

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Q. Calburn analogy is applicable for the value of Prandtl number from

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Q. Pick out the correct equation.

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Q. Steam side heat transfer co-efficient in an evaporator is in the range of __________ kcal/hr.m²°C.

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Q. Correction is applied to LMTD for __________ flow.

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Q. If h1 = inner film co-efficient and h2 = outer film co-efficient, then the overall heat transfer co-efficient is

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Q. One kilogram of water at 0°C is changed to superheated steam of one atm pressure and 300° C. The major heat consumption in the process will be to

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Q. The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe whose surface temperature remains constant is

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Q. Sensible heat of hot industrial flue gases can not be recovered by a/an

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Q. The critical radius of insulation for a spherical shell is (where, K = thermal conductivity of insulating material h₀ = heat transfer coefficient at the outer surface)

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Q. Radiator of an automobile engine is a __________ type of heat exchanger.

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Q. In pipe flow, heat is transferred from hot wall to the liquid by

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Q. Which of the following has the minimum absorptivity ?

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Q. A black body when hot, emits heat radiation of __________ wavelengths.

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Q. A composite wall consists of two plates A and B placed in series normal to the flow of heat. The thermal conductivities are kA and kB and the specific heat capacities are CPA and CPB for plates A and B respectively. Plate B has twice the thickness of plate A. At steady state, the temperature difference across plate A is greater than that across plate B, when

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Q. Vibrations in the tubes of a shell and tube heat exchanger is induced due to the

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Q. Heat transfer by conduction in the turbulent core of a fluid flowing through a heated pipe is negligible, if the value of Prandtl number is

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