geometrical optik

8/6/2019 Geometrical Optik

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Geometrical Optik

Optik Geometri


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Reflectivity

Pemantulan


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Reflectivity

Pemantulan

y When the light on an area that is not

transparent to the form q Iangle of

the normal, then the light will be reflected by the reflectionangle q rof the normal line.

y Ketika cahaya e ge ai s at bida g ya g tidak

tra spara de ga e be t k s d t data g Ui terhadapgaris or al, aka cahaya it aka dipa t lka de ga

e be t k s d t pa t l Urterhadap garis or al.


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y If the field is a plane, ie the surface area flat, then the light

rays coming and reflected light rays, are on the same fieldand the size of angle equal to the amount ofUi bounce angleUr.

y Jika bida g terseb t er paka bida g datar, yaitbida g ya g per kaa ya rata, aka berkas si ardata g da berkas si ar pa t l, berada pada bida gya g sa a da besar ya s d t data g Ui sa a de gabesar ya s d t pa t l Ur.


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So..

Jadi..

Incidence angle (q i) equal to angle the reflection(q r.), called the law of reflection.

Sudut data g (Ui ) sa a de ga sudut pa tul

(Ur.), disebut sebagai hukum pa tula .


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Types of reflection

Jenis-jenis pemantulan

y Regular reflection: flat surface, the light comes parallel rays

are reflected as a parallel

y Diffuse reflection: The surface is not flat, parallel rays come to

be reflected in all directions.

y Pema tula teratur : Permukaa rata, si ar data gsejajar aka dipa tulka sebagai si ar sejajar

y Pema tula baur : Permukaa tidak rata, si ar data g

sejajar aka dipa tulka kesegala arah.


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Spherical Mirror

A spherical mirror, as its name implies, has the

shape of a section of a sphere. This type of

mirror focuses incoming parallel rays to a point,

as demonstrated by the colored light rays.

Cermin bulat, seperti namanya, memiliki bentuk

bagian dari suatu bola. Jenis cermin

memfokuskan sinar sejajar yang masuk ke titik,

seperti yang ditunjukkan oleh sinar berwarnaterang.


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Cermin Cekung

Concave Mirror


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The incoming rays from the object are essentially parallel because thesource is assumed to be very far from the mirror. We call the image

point in this special case the focal point F and the image distance the

focal length f = R/2


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ySinar masuk dari objek pada dasarnya paralel karena sumberdiasumsikan sangat jauh dari cermin. Kami menyebutnya titikgambar dalam hal ini khusus F focal point dan jarak gambarfocal length f = R / 2


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(a) A concave mirror of radius R. The center of curvature C is located on the

principal axis. (b) A point object placed at O in front of a concave spherical

mirror of radius R, where O is any point on the principal axis farther than R

from the mirror surface, forms a real image at I. If the rays diverge from O at

small angles, they all re.ect through the same image point.


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Concave Mirror

Lateral magnification :

Mirror equation : In term of f:


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When the object is located so that the center of curvature lies between

the object and a concave mirror surface, the image is real, inverted,

andreduced in size.

Ketika objek berada sehingga pusat kelengkungan terletak di

antara objek dan permukaan cermin cekung, gambar adalah

nyata, terbalik,dan diperkecil


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When the object is located between the focal point and a concave mirror

surface, the image is virtual, upright, andenlarged.

Ketika objek terletak antara titik fokus dan permukaan cermincekung, gambar adalah maya, tegak, dan diperbesar.


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Convex Mirror

Cermin Cembung


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y On the convex mirror, the face is shaped like a leather ball, but the front of the mirror

convex curved outward. Convex mirror focal point is behind the mirror so that is virtualand is negative. Convex mirror has a characteristic spread the light (divergent). If the

rays reflecting on the convex mirror you lengthen the base, the rays will intersect at the

focal point (hotspot) in the rear mirror. In the calculation, convex mirror hotspots is

negative because it is false.

y Pada cermin cembung, bagian mukanya berbentuk seperti kulit bola, tetapi

bagian muka cermin cembung melengkung ke luar. Titik fokus cermin

cembung berada di belakang cermin sehingga bersifat maya dan bernilai

negatif. Cermin cembung memiliki sifat menyebarkan sinar(divergen). Jikasinar-sinar pantul pada cermin cembung kamu perpanjang pangkalnya, sinar

akan berpotongan di titik fokus (titik api) di belakang cermin. Pada

perhitungan, titik api cermin cembung bernilai negatif karena bersifat semu.


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Special Rays / Sinar Istimewa

A. Rays come parallel to the main axis will be reflectedas if from the point of focus. Sinar datang sejajar

dengan sumbu utama akan dipantulkan seolah

dari titik fokus.

B. Ray came as though to point the focus will be reflected

parallel to the main axis.Sinar datang seolah olah

menuju titik fokus akan dipantulkan sejajar sumbu utama.

C. Ray came to the point M(2F) will be reflected as if from

that point as well. Sinar datang menuju titik M (2F)

akan dipantulkan seolah-olah dari titik itu juga.


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y Some things to remember about convex mirror is:

- The point of focus behind the mirror, then known as the negativemirror

- The reflection ray is spreading (diverging)

- Shadow properties: reduced, virtual, upright

y Beberapa hal yang harus diingat tentang cermin cembung

adalah:

-Titik focus di belakang cermin, maka disebut cerminnegatif

- Sinar pantul bersifat menyebar (divergen)

- sifat bayangan : diperkecil, maya, tegak


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RefractionRefraction

PembiasaPembiasa


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Refraction

Pembiasan

y Refraction is the bending of light when passing through a

different medium 2

y Pembiasan adalah pembelokan cahaya ketika melewati 2medium yang berbeda.


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y If a ray of light on the field and at an angle comes (qi) of the normal

(perpendicular field), then the beam of light that enters the second

medium will be deflected.

y Jika seberkas cahaya mengenai bidang dan membentuk sudut

datang (Ui) terhadap garis normal (garis yang tegak lurus

bidang), maka berkas cahaya yang memasuki medium kedua

akan dibelokkan.


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So..

Lalu..


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y Medium in the form:

y normal Medium close to the less tight =

away from the normal

y normal Medium less tightly to the meeting

= near normal line

y Mediumnya berupa :

y Medium rapat ke kurang rapat =

menjauhi garis normal

y Medium kurang rapat ke rapat =mendekati garis normal


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PadaPada kacakaca plan parallelplan parallel

((In the glass parallel planIn the glass parallel plan ))

y Plan parallel glass or glass block is a three-dimensional pieces of

glass which is limited by sides parallel.

y Kaca plan paralel atau balok kaca adalah keping kaca tigadimensi yang dibatasi oleh sisi-sisi yang sejajar.


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y The light from air into glass pembias theparallel plan will be refracted toward normal

lines. Similarly, when the light left the other sideto refracted.Will air away from the normal refracted. Observers from the side of therefracted.Opposite will see the light from theobject shifted by refraction. Ray diffraction end

light shifts to the direction of the original.

y Cahaya dari udara memasuki sisi pembias kaca planparalel akan dibiaskan mendekati garis normal.Demikian pula pada saat cahaya meninggalkan sisi

pembias lainnya ke udara akan dibiaskan menjauhigaris normal. Pengamat dari sisi pembias yangberseberangan akan melihat sinar dari bendabergeser akibat pembiasan. Sinar bias akhirmengalami pergeseran sinar terhadap arah semula.


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Pada prisma

(In the prism)

y Prisma is also a clear object made of glass, its usefulness among others, to directthe light rays, and flipped to change the location of the shadow and describe thewhite light into colors of the spectrum (rainbow colors). The light from the airinto one of the fields will pembias prisms refracted and the while leaving other

areas refracted into the air as well.

y Prisma juga merupakan benda bening yang terbuat dari kaca,kegunaannya antara lain untuk mengarahkan berkas sinar, mengubah

dan membalik letak bayangan serta menguraikan cahaya putih menjadiwarna spektrum (warna pelangi). Cahaya dari udara memasuki salahsatu bidang pembias prisma akan dibiaskan dan pada saat meninggalkanbidang pembias lainnya ke udara juga dibiaskan.


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Pada lensa

On lens..


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Convex Lens

Le sa Cembung


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y Convex lens is subdivided into three:

y Lensa cembung dibagi lagi menjadi tiga:

1. biconvex lens / lensa cembung dua (bikonveks)

2. plano convex lens /lensa cembung datar (plan konveks)3. convex and concave lens / lensa cembung cekung (konkaf

konveks)


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1. Biconcave lens / lensa cekung dua (bikonkaf)

2. Plano concave lens / lensa cekung datar (plan konkaf)

3. Concave and convex lens / lensa cekung dan cembung (konkafkonveks)


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