In Young's double-slit experiment,which of the following phenomena occur?

Two sources produce an interference pattern which is observed on a screen,at a distance $D$ from the sources. The fringe width is $2w$. If the distance $D$ is now doubled,the fringe width will be:

The ratio of intensities at two points on the screen in Young's double slit experiment when waves from the two slits have a path difference of $0$ and $\lambda/4$ ($\lambda$ is the wavelength of light used) $(\cos 0^\circ = 1, \cos \pi/2 = 0)$.

Imagine a Young's double-slit interference experiment performed with waves associated with fast-moving electrons produced from an electron gun. The distance between successive maxima (fringe width) will decrease if:

In Young's experiment,the distance between slits is $0.28 \,mm$ and the distance between the slits and the screen is $1.4 \,m$. The distance between the central bright fringe and the third bright fringe is $0.9 \,cm$. What is the wavelength of the light used in $\mathring{A}$?

Discuss the pattern of interference fringes obtained on the screen away from the two point sources.