ch7 geom optics sept13
TRANSCRIPT
![Page 1: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/1.jpg)
Geometrical OpticsImages Formed by Plane Mirrors, Images Formed by Spherical MirrorsImages Formed by Refraction, LensesLens Aberrations The cameraThe simple magnifierThe compound microscope, The telescopeIllumination and Brightness
![Page 2: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/2.jpg)
Images Formed by Plane Mirrors
Badrul hisham Nov 13 2
![Page 3: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/3.jpg)
Badrul hisham Nov 13 3
![Page 4: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/4.jpg)
Concave Mirror
Images Formed by Spherical Mirrors
Badrul hisham Nov 13 4
![Page 5: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/5.jpg)
Locating images
Badrul hisham Nov 13 5
![Page 6: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/6.jpg)
Convex Mirror
Parallel rays striking a convex spherical mirror are reflected as if coming from a single point behind the mirror
The images formed by a convex spherical mirror are always virtual, upright, smaller and between the mirror and F
Badrul hisham Nov 13 6
![Page 7: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/7.jpg)
- Mirror equationSince therefore
Badrul hisham Nov 13 7
![Page 8: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/8.jpg)
Badrul hisham Nov 13 8
![Page 9: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/9.jpg)
Badrul hisham Nov 13 9
![Page 10: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/10.jpg)
Badrul hisham Nov 13 10
![Page 11: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/11.jpg)
Badrul hisham Nov 13 11
![Page 12: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/12.jpg)
For small angles (paraxial rays):
Image formed by refraction
(An exterior angle of any triangle equals the sum of the two opposite interior angles)
Badrul hisham Nov 13 12
![Page 13: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/13.jpg)
Badrul hisham Nov 13 13
![Page 14: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/14.jpg)
For surface 1: For surface 2:
Image for surface 1 is object for surface 2
Assuming t small p2 = -q1, Adding,
For thin lens, distances measured from centre plane,
Badrul hisham Nov 13 14
![Page 15: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/15.jpg)
LENSMAKER’S EQUATIONFor thin lenses in air,
21
111
1
RRn
f
Where, f is focal length of lens and n is refractive index of material. Radius of curvatureR { +ve for convex surfaces -ve for concave surfaces
Badrul hisham Nov 13 15
![Page 16: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/16.jpg)
(Any two rays would suffice; the point of intercept would determine the position of the image)
Thin lensesConvex lens
Badrul hisham Nov 13 16
![Page 17: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/17.jpg)
Badrul hisham Nov 13
Locating Images by Ray Tracing
Object more than F.Image characteristics:
Concave lens
17
![Page 18: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/18.jpg)
Angle AFB = angle IFI’ and AB = ho,
Triangles OAO’ and IAI’ are similar,
Equate the right sides,
Lens equation
Badrul hisham Nov 13 18
![Page 19: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/19.jpg)
Badrul hisham Nov 13 19
![Page 20: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/20.jpg)
Badrul hisham Nov 13 20
![Page 21: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/21.jpg)
Badrul hisham Nov 13 21
![Page 22: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/22.jpg)
Lenses in contact:
2nd lens:
1st lens:
Adding: Therefore
Image formed by 1st lens becomes object for 2nd lens
Badrul hisham Nov 13 22
![Page 23: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/23.jpg)
Badrul hisham Nov 13 23
![Page 24: Ch7 geom optics sept13](https://reader035.vdocuments.site/reader035/viewer/2022062320/55cc0a4cbb61eb3e798b45d6/html5/thumbnails/24.jpg)
Lens Aberrations
Spherical aberration occurs because the focal points of rays far from the principal axis of a spherical lens (or mirror) are different from the focal points of rays of the same wavelength passing near the axis.Correction?
A material’s index of refraction varies with wavelength. Because of this phenomenon, violet rays are refracted more than red rays when white light passes through a lens.Correction? Badrul hisham Nov 13 24