Heat and Mass Transfer An electric cable of aluminium conductor (k = 240 W/mK) is to be insulated with rubber (k = 0.15 W/mK). The cable is to be located in air (h = 6 W/m²). The critical thickness of insulation will be 800 mm 40 mm 25 mm 160 mm 800 mm 40 mm 25 mm 160 mm 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 Radiation Free convection Forced convection Convection Radiation Free convection Forced convection Convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Film coefficient is defined as Inside diameter of tube Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Film coefficient × Inside diameter Thermal conductivity Equivalent thickness of film Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Film coefficient × Inside diameter Thermal conductivity Equivalent thickness of film Thermal conductivity Equivalent thickness of film Specific heat × Viscosity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A designer chooses the values of fluid flow rates and specific heats in such a manner that the heat capacities of the two fluids are equal. A hot fluid enters the counter flow heat exchanger at 100°C and leaves at 60°C. A cold fluid enters the heat exchanger at 40°C. The mean temperature difference between the two fluids is 60°C 40°C 66.7°C 20°C 60°C 40°C 66.7°C 20°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The emissive power of a body depends upon its Physical nature All of these Wave length Temperature Physical nature All of these Wave length Temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A steam pipe is to be insulated by two insulating materials put over each other. For best results Inferior insulation should be put over pipe and better one over it Better insulation should be put over pipe and better one over it Both may be put in any order Whether to put inferior OIL over pipe or the better one would depend on steam temperature Inferior insulation should be put over pipe and better one over it Better insulation should be put over pipe and better one over it Both may be put in any order Whether to put inferior OIL over pipe or the better one would depend on steam temperature ANSWER DOWNLOAD EXAMIANS APP
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