Heat and Mass Transfer The total radiation from a black body per second per unit area is ________ fourth power of the absolute temperature. This statement is known as Stefan Boltzmann law. Inversely proportional to None of these Directly proportional to Equal to Inversely proportional to None of these Directly proportional to Equal to ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat is transferred by conduction, convection and radiation in Melting of ice Boiler furnaces Condensation of steam in condenser None of these Melting of ice Boiler furnaces Condensation of steam in condenser None of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In counter flow heat exchangers Both the fluids at exit are in their hottest state Both the fluids at inlet 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 exit are in their hottest state Both the fluids at inlet 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 Which of the following has maximum value of thermal conductivity? Copper Brass Aluminium Steel Copper Brass Aluminium Steel ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat of sun reaches to us according to None of these Conduction Convection Radiation None of these Conduction Convection Radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer by conduction through a thick cylinder (Q) is given by (where T₁ = Higher temperature, T₂ = Lower temperature, r₁ = Inside radius, r₂ = Outside radius, l = Length of cylinder, and k = Thermal conductivity) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] ANSWER DOWNLOAD EXAMIANS APP