Question

The wavelength of light coming from the sodium source is $589\text{nm}$. What will be its wavelength in water?

Refractive index of water $=1.33$

• A. $223\text{nm}$
• B. $333\text{nm}$
• C. $443\text{nm}$
• D. $543\text{nm}$

Answer 1

The correct option is C $443\text{nm}$

The wavelength in water is $\frac{{\lambda }_o}{\mu }$
where ${\lambda }_o$ is the wavelength in vacuum and $\mu$ is the refractive index of water.

Thus,

$\lambda$ = $\frac{589}{1.33}$ = $443\text{nm}$