Suppose you have a grating with $8300$ lines per cm$,1$cm $=0\mathrm{.}01$ m$.$ You send a beam of white light through it and observe the interference pattern on a screen at a distance of L $=2\mathrm{.}00$ mm from the grating.

The wavelength of white light is between $380\mathrm{.}0$ nm $($violet$)$ and $760\mathrm{.}0$ nm $($red$),1$nm $=10-9$ m$.$

Part A $-$ What is the separation d between two adjacent lines on the grating?

The unit is mm $=10-6$ m$.$ Keep $3$ digits after the decimal point.