Which of the following is true in $YDSE$?

White light is passed through a double slit and interference is observed on a screen $1.5 \, m$ away. The separation between the slits is $0.3 \, mm$. The first violet and red fringes are formed $2.0 \, mm$ and $3.5 \, mm$ away from the central white fringes. The difference in wavelengths of red and violet light is $.... \, nm$.

In a Young's double slit experiment,the intensity of light at each slit is $I_0$. An interference pattern is observed along a direction parallel to the line $S_1 S_2$ on screen $S$. Find the minimum,maximum,and the intensity averaged over the entire screen,respectively.

The fringe width in an interference pattern is $X$. The distance between the sixth dark fringe from one side of the central bright band to the fourth bright fringe on the other side is: (in $X$)

In Young's double-slit experiment,a monochromatic light source is used to illuminate slits $S_1$ and $S_2$. An interference pattern is obtained on the screen with a fringe width of $w$. If a mica sheet of thickness $t$ and refractive index $\mu$ is placed in front of one of the slits,the new fringe width $w'$ becomes:

In Young's experiment,the separation between the $5^{\text{th}}$ maxima and the $3^{\text{rd}}$ minima is how many times the fringe width?