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 Young's Double slit experiment,the first maxima is observed at a fixed point $P$ on the screen. Now,the screen is continuously moved away from the plane of the slits. The ratio of the intensity at point $P$ to the intensity at point $O$ (centre of the screen) is:

In $Y.D.S.E.$,the separation between the two slits $S_1$ and $S_2$ is $a$,and the screen is at a distance $x$ from the slits. The light source $S$ is moving with velocity $v$ parallel to the line joining $S_1$ and $S_2$ and is at a perpendicular distance $h$ from the plane of the slits. What is the frequency of change in brightness at the central point on the screen?

In Young's double slit experiment,if monochromatic light is replaced by white light:

$A$ Young's double slit experiment uses a monochromatic source. The shape of the interference fringes formed on a screen is

The width of one of the two slits in a Young's double slit experiment is $4$ times that of the other slit. The ratio of the maximum to the minimum intensity in the interference pattern is: (in $: 1$)