Physics - Geometrical Optics Question with Solution | TestHub

The wavelength of light in a medium of refractive index $\mu$ is given by ${\lambda }^{\prime }=\frac{\lambda }{\mu }$, where $\lambda$ is the wavelength in air.

Given $\mu =\frac{4}{3}$.

${\lambda }^{\prime }=\frac{\lambda }{4/3}=\frac{3\lambda }{4}$

Change in wavelength, $\Delta \lambda =\lambda -{\lambda }^{\prime }=\lambda -\frac{3\lambda }{4}=\frac{\lambda }{4}$

Percentage change in wavelength $=\frac{\Delta \lambda }{\lambda }\times 100=\frac{\lambda /4}{\lambda }\times 100=25\%$

Answer: $25\%$