Q. Thermal diffusivity of a material

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Q. h.D/K is called the __________ number.

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Q. Prandtl number is the ratio of

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Q. Conductance is given by(where, x = thickness, A = heat flow area, K = thermal conductivity.)

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Q. Heat flux, as defined in heat flow is analogous to __________ in electricity flow.

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Q. The wavelength at which the maximum monochromatic emissive power occurs for a black body, is (where, T = absolute temperature of the black body)

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Q. Which is the most suitable for cold viscous feed?

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Q. Dropwise condensation is promoted on a/an __________ surface.

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Q. At Pr > 1, conduction in an ordinary fluid flowing through a heated pipe is limited to the

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Q. In a single evaporator system, the steam economy __________ by creating vacuum in the evaporator.

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Q. A tank painted with which of the following coloured paints, would heat up maximum by radiation from sun ?

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Q. The separation of liquid droplets from the vapor is done by a/an __________ , in the evaporators.

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Q. If a single tube pass heat exchanger is converted to two pass, then for the same flow rate, the pressure drop per unit length in tube side will

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Q. A steel sphere of radius 0.1 m at 400°K is immersed in an oil at 300°K. If the centre of the sphere reaches 350°K in 20 minutes, how long will it take for a 0.05 m radius steel sphere to reach the same temperature (at the centre) under identical conditions ? Assume that the conductive heat transfer co-efficient is infinitely large.

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Q. Nucleate boiling is promoted

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Q. In forced circulation, the heating element is injected

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Q. If all the conditions and dimensions are same, then the ratio of velocity through the tubes of a double pass heat exchanger to that through the single pass heat exchanger is

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Q. The equation, Nst = f/2, is the __________ analogy.

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Q. Boiling point elevation for a strong and concentrated solution is found by Duhring's rule, which states that at the same pressure, the boiling point of a solution is a linear function of the __________ of pure water.

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Q. Fluid motion in the natural convection heat transfer between a solid surface and a fluid in contact with it, results from the

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