Heat and Mass Transfer Heat transfer by radiation mainly depends upon All of these Its temperature Nature of the body Kind and extent of its surface All of these Its temperature Nature of the body Kind and extent of its surface ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer All radiations in a black body are Refracted Transmitted Reflected Absorbed Refracted Transmitted Reflected Absorbed ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following property of air does not increase with rise in temperature? Thermal conductivity Dynamic viscosity Thermal diffusivity Density Thermal conductivity Dynamic viscosity Thermal diffusivity Density ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Upto the critical radius of insulation, Convective heat loss will be less than conductive heat loss Added insulation will increase heat loss Added insulation will decrease heat loss Heat flux will decrease Convective heat loss will be less than conductive heat loss Added insulation will increase heat loss Added insulation will decrease heat loss Heat flux will decrease 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 = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two long parallel surfaces each of emissivity 0.7 are maintained at different temperatures and accordingly have radiation heat exchange between them. It is desired to reduce 75% of the radiant heat transfer by inserting thin parallel shields of emissivity 1 on both sides. The number of shields should be Three One Two Four Three One Two Four ANSWER DOWNLOAD EXAMIANS APP
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