AP1200_Ch4_Optics-2Refraction-2008

AP1200_Ch4_Optics-2Refraction-2008 - AP1200 4. Optics...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Michel A. Van Hove Michel A. Van Hove WARNING: PRINTING THIS DOCUMENT WILL USE MUCH INK AND WILL NOT SHOW ANIMATIONS. AP1200 – 4. Optics Concepts AP1200 – 4. Optics Concepts 4.2 Refraction 4.2 Refraction
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 Refraction of light Refraction of light Light is refracted (changes its direction) when it crosses any change of medium i.e. when its speed changes typically refraction occurs at the interface between media we have discussed the cause of refraction in the chapter on waves refraction is always accompanied by some reflection 7
Background image of page 2
3 Refraction of light: interface Refraction of light: interface Light refraction turns a ray toward the surface normal when entering a medium with lower speed of light Light refraction turns a ray away from the surface normal when entering a medium with higher speed of light the angle of refraction increases with the angle of incidence (this follows from Huygens’ Principle) θ 1 θ 2 8
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
4 Refraction of light: wave origin Refraction of light: wave origin c 1 c 2 Consider incidence from medium with c 2 < c 1 , and find θ 1 To generate refracted wave, match = λ 2 /sin θ 2 = λ 1 /sin θ 1 Since c = λ f ( f constant): c 2 /sin θ 2 = c 1 /sin θ 1 Refractive index: n i = c / c i So: n 1 sin θ 1 = n 2 sin θ 2 Snell’s law θ 1 θ 2 θ 1 θ 2 6
Background image of page 4
5 Question 4.5: refraction by water Question 4.5: refraction by water 7 A fish swims below the surface of the water at location P. An observer at O sees the fish at 1. a greater depth than it really is. 2. the same depth. 3. a smaller depth than it really is.
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
6 Refraction of light: block, prism and lens Refraction of light: block, prism and lens A rectangular block refracts light twice, in opposite directions no net change of direction occurs A prism refracts light twice, in the same direction a net change of direction occurs Two opposite prisms reflect light rays toward each other A lens focuses light using “rounded” prisms See also http://www.ngsir.netfirms.com/englishhtm/RefractionByPrism.htm 5
Background image of page 6
7 Question 4.6: double refraction Question 4.6: double refraction 8 The observer at O views two closely spaced lines through an angled piece of plastic. To the observer, the lines appear
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/17/2011 for the course AP 1200 taught by Professor Michela.vanhove during the Spring '10 term at City University of Hong Kong.

Page1 / 23

AP1200_Ch4_Optics-2Refraction-2008 - AP1200 4. Optics...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online