Heat Transfer The Nusselt number for fully developed (both thermally and hydrodynamically) laminar flow through a circular pipe whose surface temperature remains constant is 1.66 88.66 Dependent on NRe only 3.66 1.66 88.66 Dependent on NRe only 3.66 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer In case of heat transfer by conduction in a hollow cylinder, __________ mean area is used to calculate the heat transfer rate. Either A, B or C Geometric Logarithmic Arithmetic Either A, B or C Geometric Logarithmic Arithmetic 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 5 minutes 40 minutes 10 minutes 20 minutes 5 minutes 40 minutes 10 minutes ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Value of Prandtl number for water ranges from 100 to 500 5 to 10 1000 to 2000 L to 2 100 to 500 5 to 10 1000 to 2000 L to 2 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer If the baffle spacing in a shell and tube heat exchanger increases, then the Reynolds number of the shell side fluid Increases or decreases depending on number of shell passes Decreases Remains unchanged Increases Increases or decreases depending on number of shell passes Decreases Remains unchanged Increases ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The outlet temperature of cooling water in a heat exchanger is generally not allowed to exceed above 50°C in industrial practice mainly to avoid Excessive corrosion Uneconomic LMTD Its evaporation loss Decrease in heat exchanger efficiency Excessive corrosion Uneconomic LMTD Its evaporation loss Decrease in heat exchanger efficiency ANSWER DOWNLOAD EXAMIANS APP
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