In the setup shown in the figure,the two slits,$S_1$ and $S_2$,are not equidistant from the slit $S$. The central fringe at $O$ is then

As shown in the figure,two point coherent sources $S_1$ and $S_2$ are placed at a small distance $d$ apart. The fringes formed on the screen will be .......

In Young's double slit arrangement,water is filled in the space between the screen and the slits. Then:

In a Young's double-slit experiment,the fringe width is found to be $0.4 \, mm$ when performed in air. If the entire apparatus is immersed in water,the new fringe width will be ........ (Refractive index of water $n = 4/3$).

In a double-slit experiment,the wavelength $\lambda$ of the light source is $400 \ nm$,the slit separation $d$ is $20 \ \mu m$,and the individual slit width $a$ is $4 \ \mu m$. Considering the interference of light from the two slits and the diffraction of light through each slit,find the number of bright interference fringes that lie within the central peak of the diffraction envelope.

In a double slit experiment,when light of wavelength $400 \; nm$ was used,the angular width of the first minima formed on a screen placed $1 \; m$ away was found to be $0.2^{\circ}$. What will be the angular width of the first minima if the entire experimental apparatus is immersed in water (in $^{\circ}$)? $(\mu_{water} = 4/3)$