Heat and Mass Transfer Emissivity of a white polished body in comparison to a black body is Higher Same Lower Depends upon the shape of body Higher Same Lower Depends upon the shape of body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, a body will be white when(Where a = absorptivity, p = reflectivity, x = transmissivity) P = 0, x = 0 and a = 1 P=1, T = 0 and a = 0 X = 0, a + p = 1 P = 0, x = 1 and a = 0 P = 0, x = 0 and a = 1 P=1, T = 0 and a = 0 X = 0, a + p = 1 P = 0, x = 1 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 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 The time taken to attain 63.2% of the value of initial temperature difference ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Total heat is the heat required to Change liquid into vapour Convert water into steam and superheat it Increase the temperature of a liquid or vapour Change vapour into liquid Change liquid into vapour Convert water into steam and superheat it Increase the temperature of a liquid or vapour Change vapour into liquid ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, a body will be black when (Where a = absorptivity, p = reflectivity, X = transmissivity.) P = 0, x = 0 and a = 1 X = 0, a + p = 0 P= 1, T = 0 and a = 0 P = 0, x = 1 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 0 P= 1, T = 0 and a = 0 P = 0, x = 1 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer by conduction through a thick cylinder (Q) is given by (where T₁ = Higher temperature, T₂ = Lower temperature, r₁ = Inside radius, r₂ = Outside radius, l = Length of cylinder, and k = Thermal conductivity) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
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