Heat and Mass Transfer Which of the following is the case of heat transfer by radiation? Heat received by a person from fireplace Blast furnace Heating of building Cooling of parts in furnace Heat received by a person from fireplace Blast furnace Heating of building Cooling of parts in furnace ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Reynolds number is the ratio of Inertia force to viscous force None of these Energy transferred by convection to that by conduction Kinematic viscosity to thermal diffusivity Inertia force to viscous force None of these Energy transferred by convection to that by conduction Kinematic viscosity to thermal diffusivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer by conduction through a thick sphere is given by Q = 4πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 6πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 2πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 4πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 6πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 2πkr1 r2 (T1 - T2)/ (r2 - r1) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer from a hot body to a cold body is directly proportional to the surface area and difference of temperatures between the two bodies. This statement is called Stefan's law Newton's law of cooling First law of thermodynamics Newton's law of heating Stefan's law Newton's law of cooling First law of thermodynamics Newton's law of heating ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two long parallel surfaces each of emissivity 0.7 are maintained at different temperatures and accordingly have radiation heat exchange between them. It is desired to reduce 75% of the radiant heat transfer by inserting thin parallel shields of emissivity 1 on both sides. The number of shields should be Three One Four Two Three One Four Two ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for gases are generally More than those for solids More than those for liquids Dependent on the viscosity Less than those for liquids More than those for solids More than those for liquids Dependent on the viscosity Less than those for liquids ANSWER DOWNLOAD EXAMIANS APP
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