Heat and Mass Transfer Depending on the radiating properties, a body will be black when (Where a = absorptivity, p = reflectivity, X = transmissivity.) X = 0, a + p = 0 P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 P= 1, T = 0 and a = 0 X = 0, a + p = 0 P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 P= 1, T = 0 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The time constant of a thermocouple is 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 63.2% of the value of initial temperature difference The time taken to attain the final temperature to be measured 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 63.2% 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 Reynolds number is the ratio of Kinematic viscosity to thermal diffusivity Energy transferred by convection to that by conduction None of these Inertia force to viscous force Kinematic viscosity to thermal diffusivity Energy transferred by convection to that by conduction None of these Inertia force to viscous force ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer from a hot body to a cold body is directly proportional to the surface area and difference of temperatures between the two bodies. This statement is called Newton's law of cooling Newton's law of heating First law of thermodynamics Stefan's law Newton's law of cooling Newton's law of heating First law of thermodynamics Stefan's law ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Total emissivity of polished silver compared to black body is More or less same Higher Very much lower Same More or less same Higher Very much lower Same ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In heat transfer, conductance equals conductivity (kcal/hr/sq.m/°C/cm) divided by K.cal (heat) °C (temperature) Sq. m (area) Hr (time) K.cal (heat) °C (temperature) Sq. m (area) Hr (time) ANSWER DOWNLOAD EXAMIANS APP
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