How Is Fringe Spacing Calculated in a Double-Slit Experiment?

Click For Summary
SUMMARY

The calculation of fringe spacing in a double-slit experiment involves using the formula dsinΘ = mλ for bright fringes, where d is the distance between the slits, L is the distance to the screen, and λ is the wavelength of light. In this discussion, the distance between the slits is 0.0500 nm (5.0 x 10^-11 m) and the wavelength of yellow light is 580.0 nm (5.8 x 10^-7 m). The user attempted to calculate the angle Θ using the rearranged formula but encountered an issue with the sine function exceeding its maximum value. The correct interpretation of the slit distance in meters is crucial for accurate calculations.

PREREQUISITES
  • Understanding of wave optics principles, specifically the double-slit experiment.
  • Familiarity with trigonometric functions and their applications in physics.
  • Knowledge of unit conversions, particularly between nanometers and meters.
  • Ability to manipulate and rearrange algebraic equations.
NEXT STEPS
  • Study the derivation of the double-slit interference formula dsinΘ = mλ.
  • Learn about the significance of fringe spacing in wave optics experiments.
  • Practice unit conversion techniques, especially for wavelengths and distances.
  • Explore the implications of maximum sine values in trigonometric calculations.
USEFUL FOR

Students and educators in physics, particularly those focusing on wave optics and interference patterns, as well as anyone seeking to understand the mathematical principles behind the double-slit experiment.

beibixx
Messages
8
Reaction score
0
1. The distance between two slits is 0.0500 nm and the distance to the screen is 2.50 m. What is the spacing between the central bright fringe and the first-order fringe? Use yellow light with a wavelength of 580.0 nm. Answers: a. 0.010m b. 0.029m c. 0.290m d. 0.10m
e. 0.6m

2. y =LtanΘ
dsinΘ=mλ for bright fringes

3. Use dsinΘ=mλ to find Θ and then use Θ to find y with y =LtanΘ.
I converted 580.0 nm to 5.8 x 10^-7m and 0.50nm to 5.0 x 10^-11m.
I assumed that d is distance b/t two slits being 5.0 x 10^-7m and that L was 2.5m, the distance to the screen.
Rearranging the dsinΘ=mλ I find that

Θ=sin^-1 (m(λ/d))

giving me

Θ=(1)(5.8 x 10^-7/5.0 x 10^-11)

but it doesn't work because -7>-11 right?... so then ... I'm not sure which step I got wrong.. or if my logic is completely off.
 
Physics news on Phys.org
The value d in not correct because sinθ cannot be more than 1.
 
thanks! I read the problem incorrectly is mm to meters.
 

Similar threads

Replies
4
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 6 ·
Replies
6
Views
5K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 14 ·
Replies
14
Views
6K
Replies
6
Views
3K
  • · Replies 4 ·
Replies
4
Views
3K
Replies
1
Views
4K
  • · Replies 4 ·
Replies
4
Views
2K