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 81 3 9 270 81 3 9 270 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Kirchhoff's law states that None of these The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body The total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature The wave length corresponding to the maximum energy is proportional to the absolute temperature None of these The ratio of the emissive power and absorptive power of all bodies is the same and is equal to the emissive power of a perfectly black body The total radiation from a black body per second per unit area is directly proportional to the fourth power of the absolute temperature The wave length corresponding to the maximum energy is proportional to the absolute temperature ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Total heat is the heat required to Convert water into steam and superheat it Increase the temperature of a liquid or vapour Change vapour into liquid Change liquid into vapour Convert water into steam and superheat it Increase the temperature of a liquid or vapour Change vapour into liquid Change liquid into vapour ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The time constant of a thermocouple is The time taken to attain 50% of the value of initial temperature difference The time taken to attain 63.2% of the value of initial temperature difference The time taken to attain the final temperature to be measured Determined by the time taken to reach 100°C from 0°C The time taken to attain 50% of the value of initial temperature difference The time taken to attain 63.2% of the value of initial temperature difference The time taken to attain the final temperature to be measured Determined by the time taken to reach 100°C from 0°C ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In counter flow heat exchangers Both the fluids at exit are in their hottest state Both the fluids at inlet are in their hottest state One fluid is in hottest state and other in coldest state at inlet Both the fluids at inlet (of heat exchanger where hot fluid enters) are in their coldest state Both the fluids at exit are in their hottest state Both the fluids at inlet are in their hottest state One fluid is in hottest state and other in coldest state at inlet Both the fluids at inlet (of heat exchanger where hot fluid enters) are in their coldest state ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Two balls of same material and finish have their diameters in the ratio of 2: 1 and both are heated to same temperature and allowed to cool by radiation. Rate of cooling by big ball as compared to smaller one will be in the ratio of 0.084027777777778 0.16736111111111 0.043055555555556 0.042361111111111 0.084027777777778 0.16736111111111 0.043055555555556 0.042361111111111 ANSWER DOWNLOAD EXAMIANS APP
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