Heat and Mass Transfer Wien’s law states that the wave length corresponding to ________ is proportional to the absolute temperature. Both (A) and (B) Maximum energy None of these Minimum energy Both (A) and (B) Maximum energy None of these Minimum energy ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thickness of thermal and hydrodynamic boundary layer is equal if Prandtl number is Equal to Nusselt number Less than one Equal to one Greater than one Equal to Nusselt number Less than one Equal to one Greater than one ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A cube at high temperature is immersed in a constant temperature bath. It loses heat from its top, bottom and side surfaces with heat transfer coefficients of h₁, h₂ and h₃ respectively. The average heat transfer coefficient for the cube is h₁ + h₂ + h₃ None of these 1/h₁ + 1/h₂ + 1/h₃ (h₁.h₂.h₃)1/3 h₁ + h₂ + h₃ None of these 1/h₁ + 1/h₂ + 1/h₃ (h₁.h₂.h₃)1/3 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In counter flow heat exchangers 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 exit are in their hottest state 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 One fluid is in hottest state and other in coldest state at inlet Both the fluids at exit are in their hottest state 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 Thermal conductivity of air with rise in temperature Decreases May increase or decrease depending on temperature Remain constant Increases Decreases May increase or decrease depending on temperature Remain constant Increases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Pick up the wrong case. Heat flowing from one side to other depends directly on Face area Temperature difference Thickness Time Face area Temperature difference Thickness Time ANSWER DOWNLOAD EXAMIANS APP