Heat and Mass Transfer When absorptivity (α) = 1, reflectivity (ρ) = 0 and transmissivity (τ) = 0, then the body is said to be a Grey body Black body Opaque body White body Grey body Black body Opaque body White body 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 (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) 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 amount of heat flow through a body by conduction is Dependent upon the material of the body All of these Directly proportional to the temperature difference on the two faces of the body Directly proportional to the surface area of the body Dependent upon the material of the body All of these Directly proportional to the temperature difference on the two faces of the body Directly proportional to the surface area of the body 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 Convection None of these Conduction Radiation Convection None of these Conduction Radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Stefan Boltzmann law, the total radiation from a black body per second per unit area is directly proportional to the Cube of the absolute temperature Fourth power of the absolute temperature Square of the absolute temperature Absolute temperature Cube of the absolute temperature Fourth power of the absolute temperature Square of the absolute temperature Absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Conduction is a process of heat transfer From a hot body to a cold body, in a straight line, without affecting the intervening medium From one particle of the body to another by the actual motion of the heated particles From one particle of the body to another without the actual motion of the particles None of these From a hot body to a cold body, in a straight line, without affecting the intervening medium From one particle of the body to another by the actual motion of the heated particles From one particle of the body to another without the actual motion of the particles None of these ANSWER DOWNLOAD EXAMIANS APP
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