 
                 
                InterviewSolution
 Saved Bookmarks
    				| 1. | Two spherical black bodies of radii `R_(1)` and `R_(2)` and with surface temperature `T_(1)` and `T_(2)` respectively radiate the same power. `R_(1)//R_(2)` must be equal toA. `(T_(1))/(T_(2))`B. `(T_(2))/(T_(1))`C. `((T_(1))/(T_(2)))^(3)`D. `((T_(2))/(T_(1)))^(2)` | 
| Answer» Correct Answer - C The rate at which an object radiates energy is given as, `Q/t sigma AT^(4) rArr` Power, `P = sigmaAT^(4)` `:. A prop 1/(T^(4))` It the body radiates same power, then `rArr (A_(2))/(A_(1)) = (T_(1)^(2))/(T_(2)^(4)) rArr (4pir_(2)^(2))/(4pir_(1)^(2)) = (T_(1)^(4))/(T_(2)^(4))` `:. (r_(2))/(r_(1)) = ((T_(1))/(T_(2)))^(2)` | |