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?

In Young's double-slit experiment,the maximum intensity is $I_0$. If one slit is closed,the new maximum intensity is:

$A$ Young's double-slit experimental setup is immersed in water of refractive index $1.33$. It has a slit separation of $1 \ mm$ and the distance between the slits and the screen is $1.33 \ m$. If the wavelength of incident light on the slits is $6300 \ \mathring{A}$,then the fringe width on the screen is:

In a Young's double-slit experiment,the fringe width is $0.8 \, mm$ when light of wavelength $6000 \, \mathring{A}$ is used,and the screen is at a distance of $2.5 \, m$. If the experiment is performed in a liquid with a refractive index of $1.6$,the new fringe width will be.....$mm$.

Which of the following is a true statement if,in Young's double-slit experiment,the separation between the slits is gradually increased?