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 According to Newton's law of cooling, the heat transfer from a hot body to a cold body is Either (A) or (B) Both (A) and (B) Directly proportional to the surface area Directly proportional to the difference of temperatures between the two bodies Either (A) or (B) Both (A) and (B) Directly proportional to the surface area Directly proportional to the difference of temperatures between the two bodies ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The rate of energy emission from unit surface area through unit solid angle, along a normal to the surface, is known as Emissivity Reflectivity Transmissivity Intensity of radiation Emissivity Reflectivity Transmissivity Intensity of radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The insulation ability of an insulator with the presence of moisture would Increase May increase/decrease depending on temperature and thickness of insulation Decrease Remain unaffected Increase May increase/decrease depending on temperature and thickness of insulation Decrease Remain unaffected ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following has maximum value of thermal conductivity? Brass Steel Copper Aluminium Brass Steel Copper Aluminium 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/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) ANSWER DOWNLOAD EXAMIANS APP