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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Q. Crystallisation of solids from a homogeneous solution is a/an __________ process.

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Q. A multiple effect evaporator has a capacity to process 4000 kg of solid caustic soda per day, when it is concentrating from 10% to 25% solids. The water evaporated in kg per day is

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Q. Value of Prandtl number for water ranges from

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Q. Heat transfer in the laminar sublayer in case of a liquid flowing through a pipe, is mostly by

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Q. In case of a multipass shell and tube heat exchanger, providing a baffle on the shell side __________ the heat transfer rate.

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Q. The local surface conductance for laminar film condensation on vertical surface is (where, t = film thickness)

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Q. Heat transfer co-efficient (h₁) for liquids increases with

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Q. A diathermaneous substance __________ the thermal radiation completely.

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Q. A hot body will radiate heat most rapidly, if its surface is

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Q. Evaporation of 1kg of water from a solution in a single effect evaporator requires about __________ kg of steam.

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Q. A metal wire of 0.01 m dia and thermal conductivity 200 W/m.K is exposed to a fluid stream with a convective heat transfer coefficient of 100 W/m².K. The Biot number is

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