Heat and Mass Transfer Wien’s law states that the wave length corresponding to ________ is proportional to the absolute temperature. Both (A) and (B) None of these Minimum energy Maximum energy Both (A) and (B) None of these Minimum energy Maximum energy ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for solids are generally Less than those for liquids Less than those for gases More or less same as for liquids and gases More than those for liquids and gases Less than those for liquids Less than those for gases More or less same as for liquids and gases More than those for liquids and gases ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When absorptivity (α) = 1, reflectivity (ρ) = 0 and transmissivity (τ) = 0, then the body is said to be a White body Black body Grey body Opaque body White body Black body Grey body Opaque body ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Heat transfer takes place as per Kirchoff's law First law of thermodynamic Zeroth law of thermodynamics Second law of the thermodynamics Kirchoff's law First law of thermodynamic Zeroth law of thermodynamics Second law of the thermodynamics 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 = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] Q = = 2πlk/2.3 (T₁ - T₂) log (r₂/r₁) Q = [2π (T₁ - T₂)]/2.3 lk log (r₂/r₁) Q = [2πlk (T₁ - T₂)]/2.3 log (r₂/r₁) Q = 2.3 log (r₂/r₁)/[2πlk (T₁ - T₂)] 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 Heat transfer by radiation mainly depends upon Its temperature Kind and extent of its surface Nature of the body All of these Its temperature Kind and extent of its surface Nature of the body All of these ANSWER DOWNLOAD EXAMIANS APP