Heat Transfer Choose the most important factor on which the heat conducted through a wall in a unit time will depend on? Temperature difference between the two surfaces of the wall Thickness of the wall Material of the wall Area of the wall perpendicular to heat flow Temperature difference between the two surfaces of the wall Thickness of the wall Material of the wall Area of the wall perpendicular to heat flow ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Heat transfer rate per unit area is called thermal conductivity thermal diffusivity heat flux heat transfer co-efficient thermal conductivity thermal diffusivity heat flux heat transfer co-efficient ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer In counter flow compared to parallel flow, More surface area is required for a given heat transfer rate Less surface area is required for a given heat transfer rate LMTD is greater Both A and B More surface area is required for a given heat transfer rate Less surface area is required for a given heat transfer rate LMTD is greater Both A and B ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer For large heat transfer area requirement, shell and tube heat exchanger is preferred, because it Occupies smaller space Is more economical Is easy to operate and maintain All of these Occupies smaller space Is more economical Is easy to operate and maintain All of these ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Three solid objects of the same material and of equal mass-a sphere, a cylinder (length = diameter) and a cube are at 500°C initially. These are dropped in a quenching bath containing a large volume of cooling oil each attaining the bath temperature eventually. The time required for 90% change in temperature is the smallest for Sphere Equal for all the three Cube Cylinder Sphere Equal for all the three Cube Cylinder ANSWER DOWNLOAD EXAMIANS APP
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 Average temperature of the fin Constant temperature equal to that of the base Surrounding temperature Temperature of the fin end Average temperature of the fin Constant temperature equal to that of the base Surrounding temperature Temperature of the fin end ANSWER DOWNLOAD EXAMIANS APP
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