Spacing between slits in a diffraction grating w/o known wavelength

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SUMMARY

The discussion centers on determining the distance between slits in a diffraction grating without knowing the wavelength of the light source. Key equations mentioned include X = m(lambda)L / d and dsin(theta) = m(lambda), which are essential for solving the problem. The user suggests using white light to illuminate the slit, leveraging the known limits of visible wavelengths to estimate the slit distance. The challenge lies in having two unknowns, making it difficult to isolate the slit distance, d.

PREREQUISITES
  • Understanding of diffraction grating principles
  • Familiarity with trigonometric functions in physics
  • Knowledge of light wavelength ranges, particularly visible light
  • Ability to perform measurements and calculations involving angles and distances
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  • Research methods for estimating wavelength using white light diffraction patterns
  • Learn about the application of the diffraction grating equation in experimental setups
  • Explore techniques for measuring angles accurately in optical experiments
  • Investigate the effects of different light sources on diffraction patterns
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Students and educators in physics, particularly those focused on optics and wave phenomena, as well as anyone conducting experiments involving diffraction gratings.

chanderson
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Homework Statement



I have an issue for a question I have. The problem is that I need to find the distance between the slits of a diffraction grating. Normally this would be pretty simple, but I'm not given the wavelength of the light source we're supposed to use to find it out.

Homework Equations



I know X~m(lambda)L / d and X = Ltan(theta) but this is difficult to figure out without the wavelength. I also know that dsin(theta) = m(lambda) but if I substitute that into the inital equation it eliminates d altogether.

The Attempt at a Solution



I know that if given the wavelength I could easily find d by using the initial equation and several simple measurments. I could also use the more accurate Ltan(theta) and measure the angle from the normal to the first maxima. I could set it up by setting the grating a certain distance from a blank wall and shine the light source through it, but without the wavelength I end up with two unknowns so I'm pretty much stuck.
 
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Illuminate the slit with white light. You know the limit wavelengths of the visible range.

ehild
 

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