Calculating Wavelength Using Diffraction Grating

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To calculate the wavelength of light using a diffraction grating, the setup involves measuring the distance from the grating to the light source and the distance between the zero order and first order maxima. In this case, with a distance of 1m from the grating and 0.5m between the maxima, the angle theta is determined to be 26.6 degrees. Using the formula m*wavelength=d*sin(theta) with a grating of 1000 lines per cm, the calculated wavelength is 4.48*10^-4 cm. It is noted that the grating's specifications, including the number of lines per cm, are typically provided, which is essential for accurate calculations. Understanding these principles is crucial for successfully determining the wavelength in a lab setting.
GelatinGhost
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Ok, so I'm going to have a lab final on diffraction gratings tomorrow, and I want to make sure I have the right idea. Basically we need to find out the wavelength of an unknown light using a diffraction grating.

So let's say the grating is perpendicular to the light, and the distance from the grating to the light is 1m. The distance from the zero order line (the light source?) and first order line (first maxima on the right?) is .5m. That would mean that theta is 26.6 degrees, correct? And with 1000 lines per cm (1/d), the equation m*wavelength=d*sin(theta) would be as follows:

1*wavelength=(1/1000)*sin(26.6)

making wavelength=4.48*10^-4 cm. Is this correct?

Also, is it possible to find wavelength without d? Because I'm not even sure if we're going to be given it or not.
 
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That seems fine. If you're doing an experiment the grating should have on it somewhere how many lines it has per cm etc.
 
Alright, thanks a lot!
 

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