Heat and Mass Transfer Fourier's law of heat conduction gives the heat flow for Two dimensional cases only Nonuniform temperature surfaces One dimensional cases only Irregular surfaces Two dimensional cases only Nonuniform temperature surfaces One dimensional cases only Irregular surfaces ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In regenerator type heat exchanger, heat transfer takes place by Flow of hot and cold fluids alternately over a surface A complete separation between hot and cold fluids Direct mixing of hot and cold fluids Generation of heat again and again Flow of hot and cold fluids alternately over a surface A complete separation between hot and cold fluids Direct mixing of hot and cold fluids Generation of heat again and again 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 One Four Two Three One Four Two Three ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Unit of thermal conductivity in S.I. units is W/m °K J/m² sec J/m °K sec Option (B) and (C) above W/m °K J/m² sec J/m °K sec Option (B) and (C) above 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 = [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) 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) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of the energy absorbed by the body to total energy falling on it is called Absorptivity Emissive power Emissivity Absorptive power Absorptivity Emissive power Emissivity Absorptive power ANSWER DOWNLOAD EXAMIANS APP
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