Heat Transfer Extended heat transfer surface like fins are used to increase the heat transfer rate. Fin efficiency is defined as the ratio of heat transferred across the fin surface to the theoretical heat transfer across an equal area held at the Constant temperature equal to that of the base Surrounding temperature Average temperature of the fin Temperature of the fin end Constant temperature equal to that of the base Surrounding temperature Average temperature of the fin Temperature of the fin end ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer A composite flat wall of a furnace is made of two materials 'A' and 'B'. The thermal conductivity of 'A' is twice of that of material 'B', while the thickness of layer of 'A' is half that of B. If the temperature at the two sides of the wall are 400 and 1200°K, then the temperature drop (in °K) across the layer of material 'A' is 160 133 150 125 160 133 150 125 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer A metal ball of radius 0.1 m at a uniform temperature of 90°C is left in air at 30°C. The density and the specific heat of the metal are 3000 kg/m³ and 0.4 kJ/kg.K respectively. The heat transfer co-efficient is 50 W/m².K Neglecting the temperature gradients inside the ball, the time taken (in hours) for the ball to cool to 60°C is 0.15 555 55.5 0.55 0.15 555 55.5 0.55 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer In an extended surface heat exchanger, fluid having lower co-efficient Can flow either inside or outside the tubes Flows outside the tubes Should not be used as it gives very high pressure drop Flows through the tube Can flow either inside or outside the tubes Flows outside the tubes Should not be used as it gives very high pressure drop Flows through the tube ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The ratio of the total emissive power to the absorptivity for all bodies is same at ther-mal equilibrium. This is __________ law. Kirchoffs Wien's displacement Stefan-Boltzman Planck's Kirchoffs Wien's displacement Stefan-Boltzman Planck's ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Steam traps are provided in steam carrying pipelines to condense steam none of the listed here release excess steam pressure by bleeding steam. remove condensate and inert gases condense steam none of the listed here release excess steam pressure by bleeding steam. remove condensate and inert gases ANSWER DOWNLOAD EXAMIANS APP
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