Young's double slit experiment is carried out by using green,red,and blue light,one color at a time. The fringe widths recorded are $\beta_G, \beta_R$,and $\beta_B$,respectively. Then:

In a double-slit experiment performed in air,the angular width of a fringe is found to be $0.15^{\circ}$ on a screen placed $80 \ cm$ away. The wavelength of light used is $490 \ nm$. What is the angular width of the fringe if the entire apparatus is immersed in a medium of refractive index $\frac{5}{3}$ (in $^{\circ}$)?

In Young's double slit experiment,the light emitted from the source has $\lambda = 6.5 \times 10^{-7} \, m$ and the distance between the two slits is $1 \, mm$. The distance between the screen and the slits is $1 \, m$. The distance between the third dark fringe and the fifth bright fringe will be ......... $mm$.

The fringe width in an interference pattern is $X$. The distance between the sixth dark fringe from one side of the central bright band to the fourth bright fringe on the other side is: (in $X$)

In a $YDSE$,the central bright fringe can be identified:

$A$ graph is plotted between the fringe-width $(z)$ and the distance $(D)$ between the slit and the eye-piece,keeping other parameters constant. Which of the following graphs is correct?