Physics - Wave Optics Question with Solution | TestHub

The angular width of a fringe in Young's double slit experiment is given by $\theta =\frac{\lambda }{d}$

When the apparatus is immersed in a liquid of refractive index $\mu$, the wavelength of light changes to ${\lambda }^{\prime }=\frac{\lambda }{\mu }$

The new angular width becomes ${\theta }^{\prime }=\frac{{\lambda }^{\prime }}{d}=\frac{\lambda }{\mu d}=\frac{\theta }{\mu }$

Given $\theta =0.2^{\circ }$ and $\mu =\frac{4}{3}$

${\theta }^{\prime }=\frac{0.2^{\circ }}{4/3}=0.2^{\circ }\times \frac{3}{4}=0.15^{\circ }$

Answer: $0.15^{\circ }$