1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: How to determine number of dark fringes by a single slit with only lamba and width

  1. Jan 22, 2007 #1
    1. How many dark fringes will be produced on either side of the central maximum if light ( = 553 nm) is incident on a single slit that is 5.1 10-6 m wide?

    2. sin theta = m (lamba/ W)

    lamba = wavelength
    W = slit width
    m - number of fringes

    3. I have no idea how to do this without at least an L or theta.

    Does anyone know what I am to do?
  2. jcsd
  3. Jan 22, 2007 #2
    ok, i decided to try the slit width divided by the wavelength. This gave me the correct answer.

    Is this because this is a way to determine how many wavelengths will fit through the slit and therefore how many fringes there will be?

    I just want to make sure I am using a correct theory here and that I did not just get lucky.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook