Heat and Mass Transfer The unit of Stefan Boltzmann constant is watt/cm2 °K⁴ watt/cm4 °K watt2/cm °K⁴ watt/cm3 °K watt/cm2 °K⁴ watt/cm4 °K watt2/cm °K⁴ watt/cm3 °K ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A designer chooses the values of fluid flow rates and specific heats in such a manner that the heat capacities of the two fluids are equal. A hot fluid enters the counter flow heat exchanger at 100°C and leaves at 60°C. A cold fluid enters the heat exchanger at 40°C. The mean temperature difference between the two fluids is 66.7°C 60°C 20°C 40°C 66.7°C 60°C 20°C 40°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The logarithmic mean temperature difference (tm) is given by (where Δt1 and Δt2 are temperature differences between the hot and cold fluids at entrance and exit) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer All radiations in a black body are Transmitted Refracted Reflected Absorbed Transmitted Refracted Reflected Absorbed ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The automobile radiator is a heat exchanger of Counter flow type Parallel flow type Regenerator type Cross flow type Counter flow type Parallel flow type Regenerator type Cross flow type ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following has least value of conductivity? Glass Plastic Water Air Glass Plastic Water Air ANSWER DOWNLOAD EXAMIANS APP