Heat and Mass Transfer In convection heat transfer from hot flue gases to water tube, even though flow may be turbulent, a laminar flow region (boundary layer of film) exists close to the tube. The heat transfer through this film takes place by Conduction Both convection and conduction Radiation Convection Conduction Both convection and conduction Radiation Convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The critical radius is the insulation radius at which the resistance to heat flow is Minimum None of these Maximum Zero Minimum None of these Maximum Zero 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.) X = 0, a + p = 0 P= 1, T = 0 and a = 0 P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 X = 0, a + p = 0 P= 1, T = 0 and a = 0 P = 0, x = 0 and a = 1 P = 0, x = 1 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer An electric cable of aluminium conductor (k = 240 W/mK) is to be insulated with rubber (k = 0.15 W/mK). The cable is to be located in air (h = 6 W/m²). The critical thickness of insulation will be 800 mm 40 mm 160 mm 25 mm 800 mm 40 mm 160 mm 25 mm ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When heat is transferred by molecular collision, it is referred to as heat transfer by Convection Conduction Radiation Scattering Convection Conduction Radiation Scattering 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 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ (k₁ + k₂) k₁ k₂ 2 k₁ k₂/ (k₁ + k₂) (k₁ + k₂)/ k₁ k₂ (k₁ + k₂) k₁ k₂ ANSWER DOWNLOAD EXAMIANS APP