In Young's experiment,the ratio of maximum to minimum intensities of the fringe system is $4:1$. The amplitudes of the coherent sources are in the ratio: (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 $mm$)

Statement-$1$: If white light is used in $YDSE$,then the central bright fringe will be white.
Statement-$2$: In the case of white light used in $YDSE$,all the wavelengths produce their zero-order maxima at the same position.

In Young's double-slit experiment,if $L$ is the distance between the slits and the screen upon which the interference pattern is observed,$x$ is the average distance between adjacent fringes,and $d$ is the slit separation,then the wavelength of light is given by:

In a Young's double-slit experiment,the slits are separated by $0.12 \, mm$ and the screen is at a distance of $1 \, m$. Find the distance of the $3^{rd}$ dark fringe from the center of the screen in $cm$. Given $\lambda = 6000 \, \mathring{A}$.

Write the formula for fringe width.