Turn on thread page Beta
    • Thread Starter
    Offline

    2
    ReputationRep:
    does anyone know what I have to know about refraction? there seem to be a lot of questions on it in past papers, and I can't find my notes for that chapter anywhere.

    I know sinΦc=n1/n2 and that is the critical angle

    but how to you find angle of incidence,refraction etc, and how do you draw a ray that will totally internally reflect/refract, i know it has to have an angle greater than the critical angle but i don't know which side of the line is supposed to be greater if that makes any sence, so please HELP :confused:
    Offline

    0
    ReputationRep:
    for angles of incidence and refraction the angle in question is always about the one to the normal.

    example

    you see where two θ equal each other is Total Internal Reflection

    look at attachment for what a Normal is. just perpendicular imaginary line. the blue thing shows its perpendicular, and the green angle is the angles that are incident and refraction θ.
    Attached Images
     
    Offline

    0
    ReputationRep:
    i did unit 4 and unit 7 and got unit 10 left. i thought unit 4 was a bit of a disaster for me :confused: i revised using loads of past papers and thought they were all easy but then this unit 4 was nothing like them. so i'm really disappointed with that :mad: oh well i hope unit 10 makes up, and i think unit 7 went ok :rolleyes:
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by xelprep)
    for angles of incidence and refraction the angle in question is always about the one to the normal.

    example

    you see where two θ equal each other is Total Internal Reflection

    look at attachment for what a Normal is. just perpendicular imaginary line. the blue thing shows its perpendicular, and the green angle is the angles that are incident and refraction θ.
    thanks, but say in a question where it gives you the angle of refraction as 40° and the refractive index of n1=1.5 and n2=air how do you calculate the angle of incidence?
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by xelprep)
    i did unit 4 and unit 7 and got unit 10 left. i thought unit 4 was a bit of a disaster for me :confused: i revised using loads of past papers and thought they were all easy but then this unit 4 was nothing like them. so i'm really disappointed with that :mad: oh well i hope unit 10 makes up, and i think unit 7 went ok :rolleyes:
    5 was a bit of a disaster for me as well but 9 was an even bigger disaster so i am putting all my hopes on 10 as well!
    Offline

    0
    ReputationRep:
    Hi, does anyone have the January 2005 Synoptic paper, preferably with a markscheme? If they do i would be extremely grateful if you could send it to my email: [email protected]. Thanks, ken
    • Thread Starter
    Offline

    2
    ReputationRep:
    (Original post by orangazhang)
    Hi, does anyone have the January 2005 Synoptic paper, preferably with a markscheme? If they do i would be extremely grateful if you could send it to my email: [email protected]. Thanks, ken
    hey sorry i don't have it but if you are going to try hijack my thread, could you at least offer some pearls of wisdom about the actual topic?
    Offline

    0
    ReputationRep:
    (Original post by marisad_uk)
    thanks, but say in a question where it gives you the angle of refraction as 40° and the refractive index of n1=1.5 and n2=air how do you calculate the angle of incidence?
    Ok well....

    1n2=sin(i)/sin(r) Also 1n2=n2/n1

    so, sin(i)/sin(r)=n2/n1

    so, (i)=sin-1(n2 *sin(r))/n1

    pop in your values and there you go.....

    Hope that helps
    Lucy x
    Offline

    0
    ReputationRep:
    http://antonine-education.co.uk/Phys..._2/topic_2.htm
    Have a look there
    • Thread Starter
    Offline

    2
    ReputationRep:
    Thanks everyone I have got it now role on mod10!
 
 
 
The home of Results and Clearing

3,165

people online now

1,567,000

students helped last year

University open days

  1. London Metropolitan University
    Undergraduate Open Day Undergraduate
    Sat, 18 Aug '18
  2. Edge Hill University
    All Faculties Undergraduate
    Sat, 18 Aug '18
  3. Bournemouth University
    Clearing Open Day Undergraduate
    Sat, 18 Aug '18
Poll
A-level students - how do you feel about your results?

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.