【Daily Question】Theoretical Foundation 2020.06.08
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Multiple-choice question: Monochromatic light with a wavelength of … is incident perpendicularly on a plane diffraction grating with a grating constant of …. The maximum order of the spectral lines that can be observed is: ( ) A. 2 B. 3 C. 4 D. 5 Answer: B Hint: Extra rewards will be given to those who can explain the solution process; the answer can be found in the response!
This post was last edited by h20090630 on 2020-6-8 at 13:37. From the grating formula http://admintk.100xue*.com/UpLoadImage/2013-05-07/4ead15ec-adf7-441d-9a35-43b95cefbce1.png (k=1, 2, 3, …), it can be seen that when the wavelength and grating constant remain constant, to maximize k, sinθ must be maximized; thus, sinθ is set to 1. At this time, for the URL http://admintk.100xue*.com/UpLoadImage/2013-05-07/9e5e8337-3fd6-4b9a-afd5-69c9b47c2589.png, the maximum level after rounding is 3.