A two$-$slit interference$-$diffraction pattern is observed using light with an unknown wavelength. The slits have a separation of $0\mathrm{.}200$ mm and the width of each slit is equal but unknown.

$($a$)$ The first interference maximum occurs at $0\mathrm{.}1393.$ What is the wavelength of light that produced this? Express your answer in nm$.$

$=$ nm

Your last answer was interpreted as follows:

$486\mathrm{.}2$

$($b$)$ Find the slit width $($in mm$)$ if the m$=7$ interference maximum coincides with the n$=1$ diffraction minimum.

a$=$ mm

Your last answer was interpreted as follows:

$0\mathrm{.}286$

$($c$)$ How many bright interference fringes will be seen in the central diffraction maximum

There are interference fringes visible in the central diffraction maximum.

Your last answer was interpreted as follows:

$13$

$($d$)$ How many interference maxima are visible between the n$=1$ diffraction minimum and the n$=2$ diffraction minimum on the left side of the central maximum?