Heat and Mass Transfer According to Stefan's law, the total radiation from a black body per second per unit area is proportional to T5 T T2 Absolute temperature T5 T T2 Absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The concept of overall coefficient of heat transfer is used in case of heat transfer by Radiation Convection Conduction and convection Conduction Radiation Convection Conduction and convection Conduction ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of the thickness of thermal boundary layer to the thickness of hydrodynamic boundary layer is equal to (Prandtl number) n, where n is equal to -1 =-2/3 =-1/3 1 -1 =-2/3 =-1/3 1 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two plates spaced 150 mm apart are maintained at 1000°C and 70°C. The heat transfer will take place mainly by Free convection Convection Radiation Forced convection Free convection Convection Radiation Forced convection 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 Two Four One Three Two Four One Three 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 = 6πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 2πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 4πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 6πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 2πkr1 r2 (T1 - T2)/ (r2 - r1) ANSWER DOWNLOAD EXAMIANS APP
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