Heat and Mass Transfer A perfect black body is one which Transmits all heat radiations Is black in colour Reflects all heat Absorbs heat radiations of all wave lengths falling on it Transmits all heat radiations Is black in colour Reflects all heat Absorbs heat radiations of all wave lengths falling on it ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The time constant of a thermocouple is The time taken to attain 50% of the value of initial temperature difference Determined by the time taken to reach 100°C from 0°C 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 The time taken to attain 50% of the value of initial temperature difference Determined by the time taken to reach 100°C from 0°C 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 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 Stefan's law First law of thermodynamics Newton's law of cooling Newton's law of heating Stefan's law First law of thermodynamics ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In counter current flow heat exchanger, the logarithmic temperature difference between the fluids is ________ as compared to parallel flow heat exchanger. None of these Greater Same Less None of these Greater Same Less ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When absorptivity (α) = 1, reflectivity (ρ) = 0 and transmissivity (τ) = 0, then the body is said to be a Grey body White body Black body Opaque body Grey body White body Black body Opaque body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of non-metallic amorphous solids with decrease in temperature Remain constant May increase or decrease depending on temperature Decreases Increases Remain constant May increase or decrease depending on temperature Decreases Increases ANSWER DOWNLOAD EXAMIANS APP
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