Heat and Mass Transfer If the temperature of a solid surface changes form 27°C to 627°C, then its emissive power changes in the ratio of 9 81 3 270 9 81 3 270 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Film coefficient is defined as Inside diameter of tube Equivalent thickness of film Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Film coefficient × Inside diameter Thermal conductivity Equivalent thickness of film Thermal conductivity Molecular diffusivity of momentum Thermal diffusivity Thermal conductivity Equivalent thickness of film Specific heat × Viscosity Film coefficient × Inside diameter Thermal conductivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Thermal diffusivity of a substance is All of these Inversely proportional to density of substance Inversely proportional to specific heat Directly proportional to the thermal conductivity All of these Inversely proportional to density of substance Inversely proportional to specific heat Directly proportional to the thermal conductivity ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The insulation ability of an insulator with the presence of moisture would Increase Decrease Remain unaffected May increase/decrease depending on temperature and thickness of insulation Increase Decrease Remain unaffected May increase/decrease depending on temperature and thickness of insulation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer When heat is transferred from one particle of hot body to another by actual motion of the heated particles, it is referred to as heat transfer by Conduction Convection Conduction and convection Radiation Conduction Convection Conduction and convection Radiation ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer by conduction through a thick sphere is given by Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 2πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 4πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 6πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 2πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 4πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 6πkr1 r2 (T1 - T2)/ (r2 - r1) ANSWER DOWNLOAD EXAMIANS APP