Heat and Mass Transfer The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body. This statement is known as Kirchhoff's law Planck's law Stefan's law Wien's law Kirchhoff's law Planck's law Stefan's law Wien's law ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat is closely related with Temperature Energy Entropy Liquids Temperature Energy Entropy Liquids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat is transferred by all three modes of transfer, viz. conduction, convection and radiation in Boiler Steam condenser Refrigerator condenser coils Electric heater Boiler Steam condenser Refrigerator condenser coils Electric heater 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 = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of heat flow through a body is Q = [kA (T₁ - T₂)]/x. The term x/kA is known as Thermal conductivity Thermal coefficient None of these Thermal resistance Thermal conductivity Thermal coefficient None of these Thermal resistance 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 Fourth power of the absolute temperature Cube of the absolute temperature Square of the absolute temperature Absolute temperature Fourth power of the absolute temperature Cube of the absolute temperature Square of the absolute temperature Absolute temperature ANSWER DOWNLOAD EXAMIANS APP
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