Heat and Mass Transfer In counter flow heat exchangers Both the fluids at inlet are in their hottest state Both the fluids at exit are in their hottest state One fluid is in hottest state and other in coldest state at inlet Both the fluids at inlet (of heat exchanger where hot fluid enters) are in their coldest state Both the fluids at inlet are in their hottest state Both the fluids at exit are in their hottest state One fluid is in hottest state and other in coldest state at inlet Both the fluids at inlet (of heat exchanger where hot fluid enters) are in their coldest state ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for gases are generally Dependent on the viscosity More than those for solids Less than those for liquids More than those for liquids Dependent on the viscosity More than those for solids Less than those for liquids More than those for liquids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Stefan Boltzmann law, the total radiation from a black body per second per unit area is directly proportional to the Fourth power of the absolute temperature Absolute temperature Square of the absolute temperature Cube of the absolute temperature Fourth power of the absolute temperature Absolute temperature Square of the absolute temperature Cube of the absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of heat flow through a body is Q = [kA (T₁ - T₂)]/x. The term x/kA is known as None of these Thermal conductivity Thermal resistance Thermal coefficient None of these Thermal conductivity Thermal resistance Thermal coefficient 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 Total emissivity of polished silver compared to black body is Very much lower More or less same Higher Same Very much lower More or less same Higher Same ANSWER DOWNLOAD EXAMIANS APP
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