Heat and Mass Transfer Depending on the radiating properties, a body will be black when (Where a = absorptivity, p = reflectivity, X = transmissivity.) P= 1, T = 0 and a = 0 P = 0, x = 1 and a = 0 X = 0, a + p = 0 P = 0, x = 0 and a = 1 P= 1, T = 0 and a = 0 P = 0, x = 1 and a = 0 X = 0, a + p = 0 P = 0, x = 0 and a = 1 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Stefan Boltzmann law, ideal radiators emit radiant energy at a rate proportional to Absolute temperature Square of temperature Fourth power of temperature Fourth power of absolute temperature Absolute temperature Square of temperature Fourth power of temperature Fourth power of absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The transfer of heat by molecular collision is smallest in Gases Liquids Solids None of these Gases Liquids Solids None of these 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 = 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) Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Stefan Boltzmann law, the total radiation from a black body per second per unit area is directly proportional to the Fourth power of the absolute temperature Absolute temperature Cube of the absolute temperature Square of the absolute temperature Fourth power of the absolute temperature Absolute temperature Cube of the absolute temperature Square of the absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Planck’s law holds good for polished bodies all coloured bodies All of these black bodies polished bodies all coloured bodies All of these black bodies ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS