The black body spectrum of an object `O_(1)` is such that its radiant intensity (i.e. intensity per unit wavelength interval) is maximum at a wavelength of 200 nm. Another object `O_(2)` has the maximum radiant intensity at 600 nm. The ratio of power emitted per unit area by source `O_(1)` to that of source `O_(2)` is

Options

A. `1:81`
B. `1:9`
C. `9:1`
D. `81:1`

Answer

D

Explanation

d) From Wien's displacement law,
`lambda_(m)`T=b `rArr lambda_(m) = b/t`..............(i)
From Stefan's law,
`rArr E_(1)/E_(2)=((T)(1)/T_(2))^(4) = (lambda_(m2))/(lambda_(m1)))^(4)`
`rArr E_(1)/E_(2) = (600/200)p^(4) rArr E_(1):E_(2)=81:1`