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 0.45 0.4 0.75 0.55 0.45 0.4 0.75 0.55 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Wien’s law states that the wave length corresponding to ________ is proportional to the absolute temperature. Minimum energy Both (A) and (B) Maximum energy None of these Minimum energy Both (A) and (B) Maximum energy None of these ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The thermal diffusivities for gases are generally Less than those for liquids Dependent on the viscosity More than those for solids More than those for liquids Less than those for liquids Dependent on the viscosity More than those for solids More than those for liquids ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Depending on the radiating properties, body will be transparent when(Where a = absorptivity, p = reflectivity, x = transmissivity) P = 0, x = 0 and a = 1 X = 0, a + p = 1 P = 0, x= 1, and a = 0 P=1, x = 0, and a = 0 P = 0, x = 0 and a = 1 X = 0, a + p = 1 P = 0, x= 1, and a = 0 P=1, x = 0, and a = 0 ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer Which of the following has maximum value of thermal conductivity? Aluminium Brass Steel Copper Aluminium Brass Steel Copper ANSWER DOWNLOAD EXAMIANS APP
Heat and Mass Transfer The ratio of the energy absorbed by the body to total energy falling on it is called Emissive power Emissivity Absorptive power Absorptivity Emissive power Emissivity Absorptive power Absorptivity ANSWER DOWNLOAD EXAMIANS APP