1.

A ball is coated with lamp black. Its temperature is 327^(@)C and is placed in the atmosphere at 27^(@)C , it's rate of loss of heat per unit area is R. if the temperature of the ball is 627^(@)C. Then the rate of loss of heat per unit area will be

Answer»

2R
4R
3/16 R
16/3 R

Solution :`(R_(2))/(R_(1))=(T_(2)^(4)-T_(0)^(4))/(T_(1)^(4)-T_(0)^(4))=((900^(4)-300^(4)))/((600^(4)-300^(4)))`
`=((81+9)(81-9))/((36+9)(36-9))=(90xx72)/(45xx27)=(16)/(3)`


Discussion

No Comment Found

Related InterviewSolutions