# Light of wavelength 631nm passes through a diffraction grating having 360lines/mm .

Light of wavelength 631nm passes through a diffraction grating having 360lines/mm .A.What is the total number of bright spots (indicating complete constructive interference) that will occur on a large distant screen? Solve this problem without finding the angles. (Hint: What is the largest that sinθ can be? What does this imply for the largest value of m?)B. What is the angle of the bright spot farthest from the center?