A black body is heated from27° to 127°C. The ratio of their energies of radiation emitted will be

From Stefan's law, the total radiant energy emitted per second per unit surface area of a black body is proportional to the fourth power of the absolute temperature of the body.That is E = σT4where σ is Stefan's constant.Given,initial temperature T1 = 273 + 27 = 300Kfinal temperature T2 = 127 + 273 = 400 KHence, we haveE1E2 = T41T42 = (300)4(400)4  = 81256Therefore, E1 : E2 = 81 : 256