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____________________?

Related Mcqs:

The insulation ability of an insulator with the presence of moisture would_________________?

A. increase B. decrease C. remain unaffected D. may increase/decrease depending on temperature and thickness of insulation E. none of the above...

Metals are good conductors of heat because________________?

A. their atoms collide frequently B. their atoms-are relatively far apart C. they contain free electrons D. they have high density E. all of the above...

According to Prevost theory of heat exchange ___________________?

A. it is impossible to transfer heat from low temperature source to t high temperature source B. heat transfer by radiation requires no medium C. all bodies above absolute zero emit radiation D. heat transfer in most of the cases takes place by combination of conduction, convection and radiation E. rate of heat transfer depends … According to Prevost theory of heat exchange ___________________?Read More...

In counter flow heat exchangers_________________?

A. both the fluids at inlet (of heat ex¬changer where hot fluid enters) are in their coldest state B. both the fluids at inlet are in their hot¬test state C. both the fluids .at exit are in their hottest state D. one fluid is in hottest state and other in coldest state at inlet E. … In counter flow heat exchangers_________________?Read More...

The unit of Stefan Boltzmann constant is ____________________?

A. watt/cm2 °K B. watt/cm4 °K C. watt2/cm °K4 D. watt/cm2 °K4 E. watt/cm2 °K2...