Heat and Mass Transfer Thermal diffusivity is a Dimensionless parameter All of these Physical property of a substance Function of temperature Dimensionless parameter All of these Physical property of a substance Function of temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following is the case of heat transfer by radiation? Heat received by a person from fireplace Cooling of parts in furnace Blast furnace Heating of building Heat received by a person from fireplace Cooling of parts in furnace Blast furnace Heating of building ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer from a hot body to a cold body is directly proportional to the surface area and difference of temperatures between the two bodies. This statement is called First law of thermodynamics Stefan's law Newton's law of cooling Newton's law of heating First law of thermodynamics Stefan's law Newton's law of cooling Newton's law of heating 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 = [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) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following has least value of conductivity? Plastic Air Water Glass Plastic Air Water Glass ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, a body will be black when(Where a = absorptivity, p = reflectivity, X = transmissivity.) P= 1, T = 0 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 0 P = 0, x = 1 and a = 0 P= 1, T = 0 and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 0 P = 0, x = 1 and a = 0 ANSWER DOWNLOAD EXAMIANS APP