Heat Transfer The sum of reflectivity and absorptivity for an opaque body is equal to 1 0.5 2 1 0.5 2 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Asymptotic conditions is reached, when for a fluid flowing in laminar flow through a long tube Exit-fluid temperature > wall temperature Exit fluid temperature = wall temperature Exit fluid temperature < wall temperature Graetz number > 100 Exit-fluid temperature > wall temperature Exit fluid temperature = wall temperature Exit fluid temperature < wall temperature Graetz number > 100 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The purpose of providing expansion bellows in the shell of tubular exchanger is to Impart structural strength Facilitate increase of shell length, if needed Account for the uneven expansion of shell and tube bundles Increase the heating load Impart structural strength Facilitate increase of shell length, if needed Account for the uneven expansion of shell and tube bundles Increase the heating load 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 Cylinder Sphere Equal for all the three Cube Cylinder Sphere Equal for all the three Cube ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer A 10 cm dia steam pipe, carrying steam at 180°C, is covered with an insulation (conductivity = 0.6 W/m.°C). It losses heat to the surroundings at 30°C. Assume a heat transfer co-efficient of 0.8 W/m².°C for heat transfer from surface to the surroundings. Neglect wall resistance of the pipe and film resistance of steam. If the insulation thickness is 2 cms, the rate of heat loss from this insulated pipe will be Equal to that of the uninsulated steam pipe Greater than that for uninsulated steam pipe Less than that of the uninsulated steam pipe Less than the steam pipe with 5 cms insulation Equal to that of the uninsulated steam pipe Greater than that for uninsulated steam pipe Less than that of the uninsulated steam pipe Less than the steam pipe with 5 cms insulation ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer The radiation heat flux from a heating element at a temperature of 800°C, in a furnace maintained at 300°C is 8 kW/m². The flux, when the element temperature is increased to 1000°C for the same furnace temperature is 12.0 kW/m² 11.2 kW/m² 16.5 kW/m² 14.6 kW/m² 12.0 kW/m² 11.2 kW/m² 16.5 kW/m² 14.6 kW/m² ANSWER DOWNLOAD EXAMIANS APP
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