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 = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Stefan Boltzmann law is applicable for heat transfer by Conduction and radiation combined Conduction Radiation Convection Conduction and radiation combined Conduction Radiation Convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of glass wool varies from sample to sample because of variation in Porosity All of these Composition Density Porosity All of these Composition Density ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer If the energy radiated per second per sq. cm. of the surface for wave lengths lying between λ, and λ + dλ is represented by (eλ.dλ), then eλ is called None of these Emissive power Absorptive power Emissivity None of these Emissive power Absorptive power Emissivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Fourier's law of heat conduction is (where Q = Amount of heat flow through the body in unit time, A = Surface area of heat flow, taken at right angles to the direction of heat flow, dT = Temperature difference on the two faces of the body, dx = Thickness of the body, through which the heat flows, taken along the direction of heat flow, and k = Thermal conductivity of the body) k. (dT/dx) k. A. (dx/dT) k. A. (dT/dx) k. (dx/dT) k. (dT/dx) k. A. (dx/dT) k. A. (dT/dx) k. (dx/dT) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The concept of overall coefficient of heat transfer is used in heat transfer problems of Convection Radiation Conduction Conduction and convection Convection Radiation Conduction Conduction and convection ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS