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/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) 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 = 1 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 1 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 = 1 P=1, T = 0 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The process of heat transfer from one particle of the body to another by the actual motion of the heated particles, is called Radiation None of these Convection Conduction Radiation None of these Convection Conduction ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity of a substance is All of these Directly proportional to the thermal conductivity Inversely proportional to density of substance Inversely proportional to specific heat All of these Directly proportional to the thermal conductivity Inversely proportional to density of substance Inversely proportional to specific heat ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of surface convection resistance to the internal conduction resistance is known as Prandtl number Biot number Stanton number Grashoff number Prandtl number Biot number Stanton number Grashoff number ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The radiation emitted by a black body is known as Full radiation Black radiation All of these Total radiation Full radiation Black radiation All of these Total radiation ANSWER DOWNLOAD EXAMIANS APP
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