The refractive index of plastic is $\sqrt{3}$. Calculate the angle of refraction for a ray of light incident at polarizing angle.

In a Young's double slit experiment, two coherent sources each of wavelength $500 \mathrm{nm}$ are placed $0.5 \mathrm{mm}$ apart and the screen is placed $1\mathrm{m}$ away.

$\left(\mathrm{a}\right)$ Find the fringe width of the interference pattern observed on the screen

In a Young's double slit experiment, two coherent sources each of wavelength $500 \mathrm{nm}$ are placed $0.5 \mathrm{mm}$ apart and the screen is placed $1\mathrm{m}$ away.

$\left(\mathrm{b}\right)$ Find the distance of the second dark fringe and the fourth bright fringe from the central fringe.