# The spectral emissive power E? for a body at temperature T1 is plotted against the wavelength and area under the curve is found to be A. At a different temperature T2, the area is found to be 9A. Then ?1/?2

Arun
25758 Points
4 years ago
Dear Arpit
E1 / E2 = 1/ 9 = (T1/ T2)4
hence
T1/ T2 = 1 / $\small \sqrt$3
Now
As we know, from wein’s formula –
$\small \lambda$ T = constant
Hence
$\small \lambda$1 / $\small \lambda$2 = T2 / T1
$\small \lambda$1 / $\small \lambda$2 = $\small \sqrt$3
Regards