Hey there! Sign in to join this conversationNew here? Join for free
x Turn on thread page Beta
    • Thread Starter
    Offline

    1
    ReputationRep:
    Light of wavelength λ is incident on a diffraction grating of slit seperation 4λ. What is the angle between the second order maximum and the third order maximum of the diffracted light?

    I would presume i would have to use the diffraction grating formula nλ=dsinx, but not sure how to answer the question with it.

    thanks if you can help,
    Offline

    1
    ReputationRep:
    They told you d = 4λ...
    Offline

    0
    ReputationRep:
    simon what past paper was that off
    • Thread Starter
    Offline

    1
    ReputationRep:
    cant remember, i will find out and attach a link for you
    • Thread Starter
    Offline

    1
    ReputationRep:
    its question 7 on

    http://www.aqa.org.uk/qual/gceasa/qp...W-QP-JAN08.PDF

    i will have a look at it again in the moment
    Offline

    0
    ReputationRep:
    From what you've given:

    nλ=dSinx
    nλ=4λSinx
    2λ/4λ=Sinx
    Sin^-1(2λ / 4λ) =x
    (Thats for Second maximum, do the same for third maximum)

    (Let λ be 6.5x10^07)

    Second max. 30 degrees
    Third max 48.6 degrees
    Then subtract your second maximum anagle value from your third maximum, and you should get your answer to be 18.6 degrees, and therefore B

    Jez
    Offline

    1
    ReputationRep:
    Or you just do:

    nλ = 4λsinx
    sinx = n/4

    So angular separation is arcsin(3/4) - arcsin(1/2)
 
 
 
Reply
Submit reply
Turn on thread page Beta
Updated: November 11, 2008
Poll
Are you going to a festival?

The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Write a reply...
Reply
Hide
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.