Heat and Mass Transfer The heat transfer by conduction through a thick sphere is given by Q = 6πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 4πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 2πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 6πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 4πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 2πkr1 r2 (T1 - T2)/ (r2 - r1) Q = 8πkr1 r2 (T1 - T2)/ (r2 - r1) ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer 40% of incident radiant energy on the surface of a thermally transparent body is reflected back. If the transmissivity of the body be 0.15, then the emissivity of surface is 0.4 0.45 0.55 0.75 0.4 0.45 0.55 0.75 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The heat transfer from a hot body to a cold body is directly proportional to the surface area and difference of temperatures between the two bodies. This statement is called First law of thermodynamics Newton's law of heating Stefan's law Newton's law of cooling First law of thermodynamics Newton's law of heating Stefan's law Newton's law of cooling ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The unit of overall coefficient of heat transfer is kcal/m² hr °C kcal/m hr °C kcal/m² kcal/hr °C kcal/m² hr °C kcal/m hr °C kcal/m² kcal/hr °C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following is a case of steady state heat transfer? Heating of building in winter Air preheaters None of these I.C. engine Heating of building in winter Air preheaters None of these I.C. engine ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The concept of overall coefficient of heat transfer is used in case of heat transfer by Conduction and convection Radiation Convection Conduction Conduction and convection Radiation Convection Conduction ANSWER DOWNLOAD EXAMIANS APP
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