A Pair of Narrow Slits That Are 1

Multiple Choice

A pair of narrow slits that are 1.8 mm apart is illuminated by a monochromatic coherent light source.A fringe pattern is observed on a screen 4.8 m from the slits.If the wavelength of the monochromatic light is 450 nm,what is the angular separation between adjacent dark fringes on the screen,measured in milliradians?

A) 0.15 mrad
B) 0.20 mrad
C) 0.25 mrad
D) 0.30 mrad
E) 0.36 mrad