The energy radiated from a surface Q at absolute temperature T is related as__________________?

Related Mcqs:

The non-dimensional temperature gradient in a liquid at the wall of a pipe is the ____________________?

A. Heat flux B. Nusselt number C. Prandtl number D. Schmidt number...

Indirect contact heat exchangers are preferred over direct contact heat exchangers, because_________________?

A. Heat transfer co-efficient are high B. There is no risk of contamination C. There is no mist formation D. Cost of equipment is lower...

What is the emissivity of a black body ?

A. 0 B. 1 C. 0.5 D. 0.90...

In a cooling tower, water becomes cool by________________?

A. Loosing sensible heat B. Heat transfer to surroundings C. Vaporisation due to heat loss to air D. Loosing latent heat...

A steel sphere of radius 0.1 m at 400°K is immersed in an oil at 300°K. If the centre of the sphere reaches 350°K in 20 minutes, how long will it take for a 0.05 m radius steel sphere to reach the same temperature (at the centre) under identical conditions? Assume that the conductive heat transfer co-efficient is infinitely large ?

A. 5 minutes B. 10 minutes C. 20 minutes D. 40 minutes...