A Thin Beam of Laser Light of Wavelength 514 Nm

Multiple Choice

A thin beam of laser light of wavelength 514 nm passes through a diffraction grating having 3952 lines/cm.The resulting pattern is viewed on a distant curved screen that can show all bright fringes up to and including ±90.0° from the central spot.If the experiment were performed with all of the apparatus under water (which has an index of refraction of 1.33) ,what would be the TOTAL number of bright spots that would show up on the screen?

A) 6
B) 7
C) 12
D) 13
E) 14