Question

Wavelength of the incident light is changed from $600\, nm$ to $1200 \,nm$. The intensity of the scattered light in Rayleigh scattering will become _____ times the initial scattered intensity.

Answer 1

According to Rayleigh's law of scattering,
$I \propto \frac{1}{\lambda^{4}}$
$\therefore \frac{ I _{2}}{ I _{1}}=\left(\frac{\lambda_{1}}{\lambda_{2}}\right)^{4}=\left(\frac{600 \times 10^{-9}}{1200 \times 10^{-9}}\right)^{4}$
$=\frac{1}{2^{4}}=0.0625 \approx 0.06$