Heat Transfer In thermal radiation for a black body (where, ε is emissivity and α is absorptivity) α = 1; ε ≠ 1 α ≠ 1, ε = 1 α ≠ 1, ε ≠ 1 α = 1; ε = 1 α = 1; ε ≠ 1 α ≠ 1, ε = 1 α ≠ 1, ε ≠ 1 α = 1; ε = 1 ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer For gases, the thermal conductivity increases with temperature rise. For liquids, with increase in concentration, its thermal conductivity generally Remains unchanged Increases exponentially Increases Decreases Remains unchanged Increases exponentially Increases Decreases ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer A measure of the extent to which viscous heating is important relative to the heat flow resulting from the impressed temperature difference is represented by the __________ number. Brinkman Grashoff Stantan Condensation Brinkman Grashoff Stantan Condensation ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer Thermal conductivities of most of the liquids __________ with rise in temperature. Increases Decreases May increase or decrease; depends on the liquid Remains unchanged Increases Decreases May increase or decrease; depends on the liquid Remains unchanged ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer In which mode of heat transfer, the Biot number is important? Natural convection Transient heat conduction Radiation Forced convection Natural convection Transient heat conduction Radiation Forced convection ANSWER DOWNLOAD EXAMIANS APP
Heat Transfer A 2-4 heat exchanger involves Only parallel-flow of fluids Only counter-flow of fluids Smaller pressure drop compared to 1-2 exchanger Both counter and parallel-flow of the fluids Only parallel-flow of fluids Only counter-flow of fluids Smaller pressure drop compared to 1-2 exchanger Both counter and parallel-flow of the fluids ANSWER DOWNLOAD EXAMIANS APP