Heat and Mass Transfer Thermal conductivity of air at room temperature in kcal/m hr °C is of the order of 0.02 0.01 0.002 0.1 0.02 0.01 0.002 0.1 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Planck’s law holds good for All of these polished bodies black bodies all coloured bodies All of these polished bodies black bodies all coloured bodies ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer In counter flow heat exchangers Both the fluids at inlet (of heat exchanger where hot fluid enters) are in their coldest state One fluid is in hottest state and other in coldest state at inlet Both the fluids at inlet are in their hottest state Both the fluids at exit are in their hottest state Both the fluids at inlet (of heat exchanger where hot fluid enters) are in their coldest state One fluid is in hottest state and other in coldest state at inlet Both the fluids at inlet are in their hottest state Both the fluids at exit are in their hottest state ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The logarithmic mean temperature difference (tm) is given by (where Δt1 and Δt2 are temperature differences between the hot and cold fluids at entrance and exit) tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 tm = (Δt1 - Δt2)/ loge (Δt1/Δt2) tm = tm = (Δt1 - Δt2) loge (Δt1/Δt2) tm = loge (Δt1/Δt2)/ (Δt1 - Δt2) tm = loge (Δt1 - Δt2)/ Δt1/Δt2 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, a body will be white when(Where a = absorptivity, p = reflectivity, x = transmissivity) X = 0, a + p = 1 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 = 1 P = 0, x = 0 and a = 1 P=1, T = 0 and a = 0 P = 0, x = 1 and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer According to Stefan Boltzmann law, ideal radiators emit radiant energy at a rate proportional to 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 Absolute temperature ANSWER DOWNLOAD EXAMIANS APP
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