Question

the wavelength of light in air is 7800 A. what is the wavelength of light in medium whose refractive index is 4 by 3​

Answer 1

Answer:

5850A° is the wavelength of light in medium.

Explanation:

Refractive index is defined as ratio of velocity of light in vacuum to the velocity of light in medium .

$n=\frac{c}{V}=\frac{4}{3}$ (given)

$\lambda =\frac{c}{\nu }$ ...[1] (in vacuum )

Frequency depends upon source of light not on medium . So frqqency will remain same in the medium.

$\lambda '=\frac{v}{\nu }$....[2] (in a given medium)

$\frac{\lambda}{\lambda '}=\frac{\frac{c}{\nu }}{\frac{V}{\nu }}$

$\frac{\lambda}{\lambda '}=\frac{c}{V}$

$\frac{\lambda}{\lambda '}=\frac{4}{3}$

$\lambda '=\frac{3\times \lambda }{4}=\frac{3\times 7800\AA}{4}=5850\AA$

5850A° is the wavelength of light in medium.