What is the emissivity of a black body ?

Related Mcqs:

Pick out the wrong statement ?

A. In drying a solid containing moisture above the critical moisture content the number of degrees of freedom is 2 B. Sherwood number in mass transfer corresponds to Nusselt number in heat transfer and Schmidt number to Prandtl number C. Forced convection is relatively more effective in increasing the rate of mass transfer, if Schmidt … Pick out the wrong statement ?Read More...

For large heat transfer area requirement, shell and tube heat exchanger is preferred, because it________________?

A. Occupies smaller space B. Is more economical C. Is easy to operate and maintain D. All A., B. and C....

Pick out the correct statement ?

A. Higher is the temperature of the radiating body, higher is the wavelength of radiation B. Logarithmic mean area is used for calculating the heat flow rate through a thick walled cylinder C. The wavelength corresponding to maximum mono-chromatic emissive power increases with rise in temperature D. Solid angle subtended by the finite surface at … Pick out the correct statement ?Read More...

In forced convection, the heat transfer depends on _______________?

A. Re, Pr B. Re, Gr C. Mainly Gr D. Re only...

Pick out the wrong statement ?

A. The controlling resistance in case of heating of air by condensing steam is in the air fil B. The log mean temperature difference (LMTD) for counter flow and parallel flow can be theoretically same when any one of the fluids (hot or cold fluid) passes through the heat exchanger at constant temperature C. In … Pick out the wrong statement ?Read More...