(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Visible light passes through a diffraction grating that has 900 slits per centimeter, and the interference pattern is observed on a screen that is 2.58m from the grating. In the first-order spectrum, maxima for two different wavelengths are separated on the screen by 3.16 mm . What is the difference between these wavelengths?

2. Relevant equations

d*sinΘ=mλ

3. The attempt at a solution

d = 1/90000 = 1.111*10^{-5}

d*sin(Θ_{1})=λ_{1}and d*sin(Θ_{2})=λ_{2}

using subtraction d*ΔsinΘ=Δλ (and using small angle approx d*ΔΘ=Δλ)

But im not sure how to find ΔΘ (or how even to visualize ΔΘ)

thanks in advance.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Diffraction Grating problem (waves and optics)

Have something to add?

**Physics Forums | Science Articles, Homework Help, Discussion**