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.What is the TOTAL number of bright fringes that will show up on the screen?
A) 4
B) 5
C) 8
D) 9
E) 10

Question

Quizplus · Accepted Answer

The total number of bright fringes is given by 2N+1, where N is the number of lines per centimeter. In this case, N = 3952 lines/cm, so the total number of bright fringes is 2(3952) + 1 = 7905.

A Thin Beam of Laser Light of Wavelength 514 Nm