Heat Transfer The heat transfer by radiation from a mild steel surface is to be reduced by reducing the emissivity of the surface. This can be best achieved by Painting the surface black Giving the surface a mirror finish Roughening the surface Painting the surface white (with aluminium paint) Painting the surface black Giving the surface a mirror finish Roughening the surface Painting the surface white (with aluminium paint) ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer 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 0.85 0.35 0.55 0.45 0.85 0.35 0.55 0.45 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Which of the following accessories is provided in the vapor line of an evaporator for removing the entrained liquid ? Vent Catchall None of the listed here Bleed point Vent Catchall None of the listed here Bleed point ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer In case of heat flow by conduction for a cylindrical body with an internal heat source, the nature of temperature distribution is Parabolic Hyperbolic None of these Linear Parabolic Hyperbolic None of these Linear ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer In a heat exchanger, one transfer unit means A section of the exchanger in which change in temperature of one stream equals the average driving force in the section None of these Both A and B The size of the exchanger in which heat transfer rate is 1 kcal/hr A section of the exchanger in which change in temperature of one stream equals the average driving force in the section None of these Both A and B The size of the exchanger in which heat transfer rate is 1 kcal/hr ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer 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. 20 minutes 10 minutes 40 minutes 5 minutes 20 minutes 10 minutes 40 minutes 5 minutes ANSWER DOWNLOAD EXAMIANS APP
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