Question

When sunlight is scattered by atmospheric atoms and molecules, the amount of scattered light, of wavelength 440 nm, is 'I'. What amount of light of wavelength 660 nm will be scattered?

Options

• `16/81`I

• `9/4`I

• `4/9`I

• `81/16`I

Answer 1

`underline(16/81I)`

Explanation: 

`I ∝ 1/lambda^4`

∴ `I_1/I_2 = (lambda_2^4)/(lambda_1^4)`

⇒ `I_2 = (lambda_1^4)/(lambda_2^4)I = (44)^4/(66)^4I = (2/3)^4I = 16/81I`