Diffraction Grating: Finding Wavelength with Given Angle and Slit Density

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SUMMARY

The discussion focuses on calculating the wavelength of monochromatic light using a diffraction grating with a density of 5.3x103 lines/cm and an observed first-order maximum at an angle of 17 degrees. The correct formula applied is d(sin Θ) = mλ, where d is the slit separation, m is the order of the maximum, and λ is the wavelength. The error in the initial calculation stemmed from incorrectly determining the value of d; it should be 1/(5.3x103 lines/cm) multiplied by 106 to convert to meters. The corrected wavelength calculation yields a value of approximately 530 nm.

PREREQUISITES
  • Understanding of diffraction grating principles
  • Familiarity with the equation d(sin Θ) = mλ
  • Knowledge of unit conversions, particularly between lines/cm and meters
  • Basic trigonometry for calculating sine values
NEXT STEPS
  • Study the principles of diffraction and interference patterns in optics
  • Learn about the application of diffraction gratings in spectrometry
  • Explore unit conversion techniques in physics problems
  • Investigate the significance of wavelength in different light applications
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Students studying physics, particularly those focusing on optics and wave phenomena, as well as educators looking for practical examples of diffraction grating applications.

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Homework Statement


Monochromatic light shines on the surface of a diffraction grating with 5.3x10^3 lines/cm. The first order maximum is observed at an angle of 17 (degrees). Find the wavelength.

a) 420nm c) 530nm
b) 520nm d) 550nm


Homework Equations


d(sin \Theta)=m\lambda

d= 5.3x10^lines/cm=5.3x10^3 lines/m

\Theta=17

m (the order maximum)= 1

The Attempt at a Solution


I rearranged the problem so it looked like this: \lambda=(d\Theta)/m

Since m=1, I dropped it and only worked with the numerator.

The distance between the slits is 1/53 metres so the full equation looks like this: (1/53)(sin17)= \lambda

(1/53)(.29)=\lambda
.0054716981=\lambda

Just by looking at this answer its easy to see its wrong, but why? I followed the equation, so what's up? Any help would be appreciated.
 
Physics news on Phys.org
d is not 1/5.3 it is 1/5.3 times 10 to the power of 6.
 
So my work was correct but i just needed that 10^6? thanks for the help
 

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