Q. At what value of Prandtl number, the hydrodynamic and thermal boundary layers are identical ?

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Q. A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because

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Q. Pick out the wrong statement.

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Q. When warm and cold liquids are mixed, the heat transfer is mainly by

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Q. A cube, sphere & a thin circular plate (all having same mass and made of same material) are all heated to 300°C and allowed to cool in natural air. Which one will cool the slowest ?

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Q. Vent pipes are provided in a condenser to

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Q. Heat transfer by natural convection is enhanced in system with

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Q. Grashoff number, which is defined as g . β(Ts - T∞) ρ². L³/μ², is proportional to the ratio of buoyancy force to __________ force.

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Q. Pick out the wrong statement.

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Q. For a cold dilute feed to produce thick viscous liquor, backward feeding as compared to forward feeding results in

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Q. Economy of an evaporator is influenced by the

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Q. For a fluid flowing in an annulus space, the wetted perimeter for heat transfer and pressure drop are

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Q. During crystallisation, formation of crystal can occur in __________ solution only.

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Q. An evaporator while concentrating an aqueous solution from 10 to 40% solids evaporates 30000 kg of water. The amount of solids handled by the system in kg is

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Q. An insulator should have

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Q. In a backward feed multiple effect evaporator

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Q. The Grashoff number is defined as the ratio of the

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Q. According to Reynolds analogy, Stanton number is equal to (where, f = Fanning friction factor)

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Q. The absorptivity of a body is equal to its emissivity

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Q. Absorptivity and refletivity of a perfect black body are respectively

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