Heat and Mass Transfer When α is absorptivity, ρ is reflectivity and τ is transmissivity, then for a diathermanous body, α = 1, ρ = 0 and τ = 0 α + ρ = 1 and τ = 0 α = 0, ρ = 1 and τ = 0 α = 0, ρ = 0 and τ = 1 α = 1, ρ = 0 and τ = 0 α + ρ = 1 and τ = 0 α = 0, ρ = 1 and τ = 0 α = 0, ρ = 0 and τ = 1 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, body will be transparent when (Where a = absorptivity, p = reflectivity, x = transmissivity) X = 0, a + p = 1 P = 0, x= 1, and a = 0 P=1, x = 0, and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 1 P = 0, x= 1, and a = 0 P=1, x = 0, and a = 0 P = 0, x = 0 and a = 1 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In a heat exchanger with one fluid evaporating or condensing, the surface area required is least in Counter flow Cross flow Parallel flow All of these Counter flow Cross flow Parallel flow All of these 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 Heat conducted through per unit area and unit thick face per unit time when temperature difference between opposite faces is unity, is called Thermal resistance Thermal conductivity Temperature gradient Thermal coefficient Thermal resistance Thermal conductivity Temperature gradient Thermal coefficient ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Prevost theory of heat exchange All bodies above absolute zero emit radiation It is impossible to transfer heat from low temperature source to t high temperature source Heat transfer in most of the cases takes place by combination of conduction, convection and radiation Heat transfer by radiation requires no medium All bodies above absolute zero emit radiation It is impossible to transfer heat from low temperature source to t high temperature source Heat transfer in most of the cases takes place by combination of conduction, convection and radiation Heat transfer by radiation requires no medium ANSWER DOWNLOAD EXAMIANS APP
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