Physics - Wave Optics Question with Solution | TestHub

When the double slit experiment is immersed in a liquid of refractive index $\mu$, the wavelength of light in the medium becomes ${\lambda }^{\prime }=\frac{\lambda }{\mu }$.

The fringe width $\beta$ is given by the formula:

$\beta =\frac{{\lambda }^{\prime }D}{d}=\frac{\lambda D}{\mu d}$

Given values are:
$\lambda =6300\text{ A˚}=6300\times 10^{-10}\text{ m}$
$D=1.33\text{ m}$
$\mu =1.33$
$d=1\text{ mm}=10^{-3}\text{ m}$

Substituting these values into the formula:

$\beta =\frac{6300\times 10^{-10}\times 1.33}{1.33\times 10^{-3}}$

$\beta =\frac{6300\times 10^{-10}}{10^{-3}}$

$\beta =6300\times 10^{-7}\text{ m}$

$\beta =6.3\times 10^{-4}\text{ m}$

Answer: $6.3\times 10^{-4}$ m