Question

2 metal spheres have radii r and 2r and emit thermal radiation with max. intensifies at wavelength lemda and 2 lemda. The respective ratio of radiant energy emitted by the per second

Answer 1

The respective ratio of radiant energy emitted by the per second is 4:1.

Let the intensities at wavelengths be = λ and 2 λ.

Power = P = σT4A

For the first metal sphere, -

λT = K

λT1 = K

T1 = T

For the second metal sphere, -

2 λT2 = K

T2 = T/2

The power for both the metals will be -

p1 α T1² r² and p2 α T2² r²

P2 α ( T/2)² (2r)²

Thus,

P1/P2 = E1/E2

= 4:1

Thus, the respective ratio is 4:1

Answer 2

Answer: 4:1

Explanation:

Use Stefan's law and Wein's displacement to solve this question and you'll get the answer. Hope this helps. :)