Narrow, equally spaced vertical slits with equal widths are located at a distance of $\backslash ($ D$=2\mathrm{.}17\backslash$mathrm$\{$~m$\}\backslash )$ from a screen. The intensity pattern in the figure is observed when light with wavelength $\backslash (=570\backslash$mathrm$\{$~nm$\}\backslash )$ from a laser passes through the slits, illuminating them uniformly. The screen is perpendicular to the laser beam.

$4$: The number of slits is $...$

You are correct.

Your receipt no$.$ is $\backslash (158-5523\backslash )$

Previous Tries

Calculate the center to center spacing between the slits. Use the cm scale to measure distances on the screen.

$\backslash (1\mathrm{.}24\backslash$times $10^\{\backslash$wedge$\}(-4)\backslash$mathrm$\{$m$\}\backslash )$

There is a fixed relation between wavelength, slit separation, and angle between the first $($or second, third etc$)$ order maximum and the central maximum. The angle can be determined from the distance to the screen and the separation between the first maximum and the central maximum on the screen.

Incorrect. Tries $\backslash (3/5\backslash )$ Previous Tries

Calculate the width of the slits. Use the cm scale to measure distances on the screen.

$\backslash (61\mathrm{.}8\backslash$times $10^\{\backslash$wedge$\}(-6)\backslash$mathrm$\{$m$\}\backslash )$

There is a fixed relation between wavelength, slitwidth, and angle between the first minimum due to the slit width and the central maximum. There is a difference between the minima due to the slit to slit interference and the minima due to the diffraction due to the slit widths. Compare with the figure of the previous problem. The angle can be determined from the distance to the screen and the separation between the first minimum and the central maximum on the screen.