Heat and Mass Transfer Thermal diffusivity is A dimensionless parameter Function of temperature Used as mathematical model A physical property of the material A dimensionless parameter Function of temperature Used as mathematical model A physical property of the material ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer by conduction through a thick sphere is given by Q = 2πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 4πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 6πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 2πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 4πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 6πkr1 r2 (T1 - T2)/ (r2 - r1) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal conductivity of water in general with rise in temperature May increase or decrease depending on temperature Decreases Increases Remain constant May increase or decrease depending on temperature Decreases Increases Remain constant ANSWER DOWNLOAD EXAMIANS APP
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 Radiation Conduction Both convection and conduction Convection Radiation Conduction Both convection and conduction Convection ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In heat transfer, conductance equals conductivity (kcal/hr/sq.m/°C/cm) divided by °C (temperature) K.cal (heat) Sq. m (area) Hr (time) °C (temperature) K.cal (heat) Sq. m (area) Hr (time) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The total emissivity power is .defined as the total amount of radiation emitted by a black body per unit Thickness Time Temperature Area Thickness Time Temperature Area ANSWER DOWNLOAD EXAMIANS APP
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