Heat and Mass Transfer The total emissivity power is .defined as the total amount of radiation emitted by a black body per unit Temperature Area Time Thickness Temperature Area Time Thickness ANSWER DOWNLOAD EXAMIANS APP
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 Stefan's law Wien's law Planck's law Kirchhoff's law Stefan's law Wien's law Planck's law ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A composite slab has two layers of different materials with thermal conductivities k₁ and k₂. If each layer has the same thickness, then the equivalent thermal conductivity of the slab will be (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ k₁ k₂ 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ k₁ k₂ 2 k₁ k₂/ (k₁ + k₂) 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 None of these Thermal coefficient Thermal resistance Thermal conductivity None of these Thermal coefficient Thermal resistance ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Stefan Boltzmann law, ideal radiators emit radiant energy at a rate proportional to Fourth power of absolute temperature Fourth power of temperature Absolute temperature Square of temperature Fourth power of absolute temperature Fourth power of temperature Absolute temperature Square of temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two balls of same material and finish have their diameters in the ratio of 2: 1 and both are heated to same temperature and allowed to cool by radiation. Rate of cooling by big ball as compared to smaller one will be in the ratio of 0.084027777777778 0.043055555555556 0.16736111111111 0.042361111111111 0.084027777777778 0.043055555555556 0.16736111111111 0.042361111111111 ANSWER DOWNLOAD EXAMIANS APP
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