Heat and Mass Transfer If the temperature of a solid surface changes form 27°C to 627°C, then its emissive power changes in the ratio of 270 9 81 3 270 9 81 3 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for gases are generally More than those for solids Less than those for liquids Dependent on the viscosity More than those for liquids More than those for solids Less than those for liquids Dependent on the viscosity More than those for liquids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The time constant of a thermocouple is The time taken to attain 63.2% of the value of initial temperature difference Determined by the time taken to reach 100°C from 0°C The time taken to attain 50% of the value of initial temperature difference The time taken to attain the final temperature to be measured The time taken to attain 63.2% of the value of initial temperature difference Determined by the time taken to reach 100°C from 0°C The time taken to attain 50% of the value of initial temperature difference The time taken to attain the final temperature to be measured ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat conducted through per unit area and unit thick face per unit time when temperature difference between opposite faces is unity, is called Thermal conductivity Thermal resistance Temperature gradient Thermal coefficient Thermal conductivity Thermal resistance Temperature gradient Thermal coefficient ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of surface convection resistance to the internal conduction resistance is known as Biot number Stanton number Grashoff number Prandtl number Biot number Stanton number Grashoff number Prandtl number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Kirchoff's law, the ratio of emissive power to absorptivity for all bodies is equal to the emissive power of a Grey body Black body Red hot body Brilliant white polished body Grey body Black body Red hot body Brilliant white polished body ANSWER DOWNLOAD EXAMIANS APP
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