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 $: 1$)

In Young's double slit experiment,the slits are $2\, mm$ apart and are illuminated by light of two wavelengths $\lambda_1 = 12000\, \mathring{A}$ and $\lambda_2 = 10000\, \mathring{A}$. At what minimum distance from the common central bright fringe on the screen $2\, m$ from the slits will a bright fringe from one interference pattern coincide with a bright fringe from the other? (in $mm$)

In Young's double-slit experiment,the separation between the two slits is $3 \, mm$ and they are illuminated by light of wavelength $480 \, nm$. The screen is at a distance of $2 \, m$ from the plane of the slits. Find the separation between the $8^{th}$ bright fringe and the $3^{rd}$ dark fringe with respect to the central bright fringe.

In Young's double slit interference experiment,the slit separation is made $3$ fold. The fringe width becomes

Two slits separated by $0.5 \,mm$ are illuminated by light of wavelength $500 \,nm$. The screen is at a distance of $120 \,cm$ from the slits. The phase difference between the interfering waves at a point $3 \,mm$ on the screen from the central bright fringe is ........... .

In an interference experiment, the $m^{th}$ bright fringe for light of wavelength $\lambda_1$ coincides with the $n^{th}$ dark fringe for light of wavelength $\lambda_2$. The ratio $\frac{\lambda_2}{\lambda_1}$ is