AskIITians Expert Hari Shankar IITD
Last Activity: 15 Years ago
By STefan-Boltzmann law, Rate of heat radiation E is proportional to T4 .
Let E = kT4.
Also, let the iniotial energy radiated be E1.
Temperature T = 400 C = 400+273 K = 673 K
So, E1 = k (673)4 .................(1)
Let rate of heat radiation be 2E1 at temperature T2.
Then, 2E1 = k(T2)4
2E1 = [E1/(673)4] (T2)4 using (1)
(T2)4 = 2 (673)4
T2 = (2)1/4 * 673 = 1.19 * 673 = 800.33 K