A diffraction grating has $5510$ lines$/$cm $.$ When a beam of monochromatic light goes through it$,$ the second pair of bright spots occurs at $26\mathrm{.}0$ cm from the central spot on a screen $42\mathrm{.}6$ cm past the grating.

PART A :

What is the wavelength of this light in nm$?$

$=$

PART B :

How far from the central spot does the next pair of bright spots occur on the screen in degrees?

$|$$3|=$