Heat and Mass Transfer Depending on the radiating properties, body will be transparent when (Where a = absorptivity, p = reflectivity, x = transmissivity) X = 0, a + p = 1 P = 0, x = 0 and a = 1 P=1, x = 0, and a = 0 P = 0, x= 1, and a = 0 X = 0, a + p = 1 P = 0, x = 0 and a = 1 P=1, x = 0, and a = 0 P = 0, x= 1, and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer A steam pipe is to be insulated by two insulating materials put over each other. For best results Both may be put in any order Inferior insulation should be put over pipe and better one over it Whether to put inferior OIL over pipe or the better one would depend on steam temperature Better insulation should be put over pipe and better one over it Both may be put in any order Inferior insulation should be put over pipe and better one over it Whether to put inferior OIL over pipe or the better one would depend on steam temperature Better insulation should be put over pipe and better one over it 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 160 mm 25 mm 40 mm 800 mm 160 mm 25 mm 40 mm 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 Zero Maximum Minimum None of these Zero Maximum ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The logarithmic mean temperature difference (tm) is given by (where Δt1 and Δt2 are temperature differences between the hot and cold fluids at entrance and exit) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity is A dimensionless parameter A physical property of the material Used as mathematical model Function of temperature A dimensionless parameter A physical property of the material Used as mathematical model Function of temperature ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS