Chapter 5 Light
2.1 Arah Mata Angin 5.1 Understanding The Reflection Of Light
ITeach – Physics Form 4
Chapter 5 Light
Understanding The Reflection Of Light Image Formed By A Plane Mirror
Characteristics of the image formed by a plane mirror
upright
laterally inverted
ITeach – Physics Form 4
virtual
same size as the object
Distance of image to mirror same as distance from object to mirror
Bab 5 Cahaya
Memahami Pantulan Cahaya Imej yang Dibentukkan Oleh Cermin Satah Ciri-ciri imej yang dibentukkan oleh cermin satah:
Tegak
Songsang sisi
ITeach – Fizik Tingkatan 4
Maya
Saiz imej sama dengan saiz objek
Jarak imej dari cermin adalah sama dengan jarak objek dari cermin
Chapter 5 Light
Understanding The Reflection Of Light The Laws Of Reflection
le
ct
ed
r
y ra
Re f
t en cid In
i
ra y
normal
Plane mirror
Incident ray
the ray of light directed at the plane mirror
Reflected ray
the ray of light that is reflected by the plane mirror
Normal
a line drawn perpendicularly to the plane mirror at the point the incident ray strikes the mirror
Angle of incidence, i Angle of reflection, r
the angle between the incident ray and the normal the angle between the reflected ray and the normal
The laws of reflection states that : The incident ray, reflected ray and the normal all lies on the same plane The angle of incidence is equal to the angle of reflection, i = r ITeach – Physics From 4
Bab 5 Cahaya
Memahami Pantulan Cahaya Hukum Pantulan Cahaya
r
ju tu
Si na r
r na Si
i
pa nt ul a
n
normal
Cermin satah Sinar tuju
sinar cahaya yang dihalakan ke arah cermin satah
Sinar pantulan
sinar cahaya yang dipantulkan oleh cermin satah
Normal
satu garisan yang dilukis berserenjang dengan cermin satah pada titik di mana sinar tuju menghala ke cermin
Sudut tuju, i
sudut di antara sinar tuju dan normal
Sudut pantulan, r
sudut di antara sinar pantulan dan normal
Hukum pantulan cahaya menyatakan bahawa : Sinar tuju, sinar pantulan dan normal berada dalam satah yang sama Sudut tuju bersamaan dengan sudut pantulan, i = r ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Ray Diagram Of Reflection Light
P
Object
Q
Image
Steps to draw the ray diagram i.
Draw the image on the other side of the mirror
ii. Draw light rays from the image to the observer’s eye iii. Draw light rays from the object to the points where the light rays in (ii) touches the mirror. ITeach – Physics From 4
Bab 5 Cahaya
Memahami Pantulan Cahaya Gambar Rajah Sinar Pantulan Cahaya
P
Objek
Q
Imej
Langkah-langkag untuk melukis gambar rajah sinar: i.
Lukis imej pada bahagian cermin yang bertentangan dengan gambar objek
ii. Lukis sinar cahaya daripada imej ke mata pemerhati iii. Lukis sinar cahaya daripada objek ke titik dimana sinar cahaya (ii) menyentuh cermin. ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Convex Mirror
Spherical mirrors can be imagined as a portion of a sphere which was sliced away and then silvered on one of the sides to form a reflecting surface.
Convex mirrors were silvered on the outside of the sphere.
ITeach – Physics From 4
Bab 5 Cahaya
Memahami Pantulan Cahaya Cermin Cembung
Cermin berbentuk sfera boleh dibayangkan seperti sebahagian sfera yang telah dipotong dan kemudian salah satu sisinya disadur perak untuk membentuk permukaan yang memantul cahaya.
Cermin cembung di sadur perak pada bahagian luar sfera
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light
Reflecting surface Virtual rays
Anatomy Of A Convex Mirror
principal axis
light diverged
P
F
C
Virtual principal focus
Pole, P
The centre point of the curved mirror
Centre of curvature, C
The geometric centre of a hollow sphere which the mirror is made
Principal axis
A straight line that passes through the pole, P and the centre of curvature, C
Radius of curvature, The distance from the pole, P to the centre of CP curvature,C Principal focus, F
A point on the principal axis through which all rays parallel to the principal axis appear to diverge from after being reflected.
Focal length. f
The distance from the pole, P and the principal focus, F
ITeach – Physics From 4
Bab 5 Cahaya
Memahami Pantulan Cahaya
Permukaan memantul Sinar maya
Anatomi Cermin Cembung
Paksi utama
P
Cahaya mencapah
Kutub, P
F
C
Fokus utama maya
Titik pusat cermin melengkung
Pusat kelengkungan, Pusat geometri sfera melengkung di mana cermin C dibuat Paksi utama
Garis yang melalui kutub, P dan pusat kelengkungan, C
Jejari CP
Jarak di antara kutub, P ke pusat kelengkungan,C
kelengkungan,
Fokus utama, F
Titik pada paksi utama di mana semua sinar yang selari dengan paksi utama mencapah selepas dipantulkan.
Panjang fokus. f
Jarak di antara kutub, P dan fokus utama, F
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Reflection Of Light By A Convex Mirror
The laws of reflections are obeyed.
F
C
a) A light ray which is directed to the centre of curvature C is reflected along its original path.
ITeach – Physics From 4
F
C
b) A light ray which is parallel to the main axis is reflected back as though it originates from the focus.
F
C
c) A ray light which is directed (or incident) to the focus F is reflected back in parallel to the main axis.
Bab 5 Cahaya
Memahami Pantulan Cahaya Pantulan Cahaya Oleh Cermin Cembung
Hukum pantulan cahaya dipatuhi
F
C
a) Satu sinar cahaya yang di arahkan ke pusat kelengkungan C dipantulkan oleh cermin mengikut lintasan yang sama. ITeach – Fizik Tingkatan 4
F
C
b) Satu sinar cahaya yang selari dengan paksi utama dipantulkan oleh cermin melallui titik fokus.
F
C
c) Satu sinar cahaya yang diarahkan (dituju) ke titik fokus F dipantulkan cermin selari dengan paksi utama.
Chapter 5 Light
Understanding The Reflection Of Light Characteristics Of Image Formed By A Convex Mirror
P O
P I F
C
I F
O
When The object is farther away from mirror.
C
The object is closer to the mirror.
Virtual
Virtual
Upright
Upright
Diminished
Diminished and bigger
Behind the mirror
Behind the mirror
ITeach – Physics From 4
Bab 5 Cahaya
Memahami Pantulan Cahaya Pantulan Cahaya Oleh Cermin Cekung
C
F
a) Satu sinar cahaya melalui pusat kelengkungan dipantulkan oleh cermin mengikut lintasan yang sama.
ITeach – Fizik Tingkatan 4
C
F
b) Satu sinar cahaya yang melalui titik fokus F dipantulkan oleh cermin selari dengan paksi utama.
C
F
c) Satu sinar cahaya yang selari dengan paksi utama dipantulkan oleh cermin melalui titik fokus F.
Bab 5 Cahaya
Memahami Pantulan Cahaya Ciri – ciri Imej yang Dibentuk Oleh Cermin Cembung
P O
P I F
C
I F
O
Apabila objek berada jauh daripada cermin
C
Objek berada dekat dengan cermin
Maya
Maya
Tegak
Tegak
Lebih kecil daripada objek
Lebih kecil daripada objek
Dibelakang cermin
Dibelakang cermin
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Concave Mirror
Spherical mirrors can be imagined as a portion of a sphere which was sliced away and then silvered on one of the sides to form a reflecting surface.
Convex mirrors were silvered on the inside of the sphere.
ITeach – Physics From 4
Bab 5 Cahaya
Memahami Pantulan Cahaya Cermin Cekung
Cermin berbentuk sfera boleh dibayangkan seperti sebahagian daripada sfera yang telah dipotong kemudiannya di sadur perak pada salah satu bahagiannya untuk membentuk permukaan yang memantul cahaya.
Cermin cekung disadur perak pada bahagian dalam sfera.
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Reflection Of Light By A Concave Mirror
C
F
a) A light ray passing through the centre of curvature is reflected back along its original path.
ITeach – Physics From 4
C
F
b) A ray of light passing through the focus F is reflected parallel to the main axis.
C
F
c) A light ray that is parallel to the main axis is reflected through the main focus F.
Chapter 5 Light
Understanding The Reflection Of Light Reflection Of Light By A Concave Mirror
O
C
F
P
I Image Formed By An Object Located Beyond The Centre Of Curvature (C) Always be located somewhere in between the centre of curvature and the focal point. inverted image (If the object is right-side up, then the image is upside down) reduced in size ITeach – Physics From 4
Bab 5 Cahaya
Memahami Pantulan Cahaya Pantulan Cahaya Oleh Cermin Cekung
O
C
F
P
I Imej yang Dibentuk Oleh Obejk Pada Kedudukan Melampaui Pusat Kelengkungan (C) Sentiasa terletak di antara pusat kelengkungan dan titik fokus. Imej songsang (Jika objek adalah disebelah kanan dan ke atas, imej disebelah kiri ke bawah) Lebih kecil daripada objek ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Reflection Of Light By A Concave Mirror
O
C
F
P
I Image Formed By An Object Located At The Centre Of Curvature (C) The image will also be located at the centre of curvature. inverted image (If the object is right-side up, then the image is upside down) The image dimensions are equal to the object. ITeach – Physics From 4
Bab 5 Cahaya
Memahami Pantulan Cahaya Pantulan Cahaya Oleh Cermin Cekung
O
C
F
P
I Imej yang Dibentuk Oleh Objak Pada Pusat Kelengkungan (C) ďƒ˜ Imej juga terletak di pusat kelengkungan. Imej songsang (jika objek adalah di bahagian kanan dan ke atas, imej yang terbentuk berada di kiri dan ke bawah) Sama saiz dengan objek ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Reflection Of Light By A Concave Mirror
I
C
O
F
P
Image Formed By An Object Located Beyond The Centre Of Curvature (C) The image will be located beyond the centre of curvature. inverted image (If the object is right-side up, then the image is upside down) The image dimensions are larger than the object. ITeach – Physics From 4
Bab 5 Cahaya
Memahami Pantulan Cahaya Pantulan Cahaya Oleh Cermin Cekung
I
C
O
F
P
Imej yang Dibentuk Oleh Objek Pada Kedudukan Diantara Pusat Kelangkungan, C dan Fokus Utama, F Imej terletak melampaui pusat kelengkungan. Imej songsang (jika objek berada pada bahagian kanan dan ke atas, imej terbentuk di bahagian kiri dan ke bawah) Imej lebih besar daripada objek. ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Image Formed By An Object Located Beyond The Centre Of Curvature (C)
C
r Pa
el al l
to
F O
P
y nit i f in
the image is formed at infinity. As the light rays from the same point on the object will reflect off the mirror and neither converge nor diverge. After reflecting, the light rays are travelling parallel to each other. virtual ITeach – Physics From 4
upright
magnified
Bab 5 Cahaya
Memahami Pantulan Cahaya Imej yang Dibentuk Oleh Objek Di Kedudukan Fokus Utama, F
C
la Se
ri
g h in
F O
ga
P
i nit i f in
Imej terbentuk di infiniti. Sinar cahaya dari titik yang sama pada objek akan memantulkan imej dari cermin dan tidak akan mencapah atau menumpu pada cermin. Selepas pantulan, sinar cahaya bergerak selari antara satu sama lain. Maya ITeach – Fizik Tingkatan 4
Tegak
Lebih besar daripada objek
Chapter 5 Light
Understanding The Reflection Of Light Image Image Formed Formed By By Object Object Located Located Between Between The The Pole, Pole, PP And And The The Focal Focal Point Point (F) (F) The image will always be located somewhere on the opposite side of the mirror. The image will always be located behind the mirror.
In this case, the image will be an upright virtual image. In this case, the image is magnified; in other words, the image dimensions are greater than the object
ITeach – Physics From 4
C
F
O
P
I
Bab 5 Cahaya
Memahami Pantulan Cahaya Imej Imej yang yang Dibentuk Dibentuk Oleh Oleh Objek Objek yang yang Terletak Terletak Di Di Antara Antara Kutub, Kutub, PP dan dan Titik Titik Fokus Fokus (F) (F)
Imej terbentuk pada sebelah yang berlainan daripada cermin.
Imej terbentuk cermin.
di
belakang
Dalam keadaan ini, imej adalah tegak dan maya. Dalam keadaan ini, imej adalah lebih besar daripada objek. Dalam kata lain, dimensi imej lebih besar daripada objek.
ITeach – Fizik Tingkatan 4
C
F
O
P
I
Chapter 5 Light
Understanding The Reflection Of Light Reflection Of Light By A Concave Mirror Pa for ralle dis l lig tan ht t o bje ct
C
F
P
I Image Formed By Object Located At Infinity Real Inverted Diminished (size of image is smaller that the size of the object) ITeach – Physics From 4
Bab 5 Cahaya
Memahami Pantulan Cahaya Pantulan Cahaya Oleh Cermin Cekung Sin ar jau caha h y ad a d ala ari h se obje lar k i
C
F
P
I Imej yang Dibentuk Oleh Objek Pada Kedudukan Infiniti Nyata Songsang Saiz imej lebih kecil daripada objek ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Applications Of Of Reflection Reflection Of Of Light Light -- Plane Plane Mirror Mirror Applications
To reflect light from the object into the eye of an observer to produce a virtual, upright image.
To enable the dentist to see the back portion of the patient’s teeth.
Periscope
Normally found inside closet for customers to try out clothings
Full length mirror ITeach – Physics From 4
Dental mirror
Bab 5 Cahaya
Memahami Pantulan Cahaya Aplikasi Pantulan Pantulan Cahaya Cahaya –– Cermin Cermin Satah Satah Aplikasi Memantulkan cahaya daripada objek ke mata pemerhati bagi menghasilkan imej maya dan tegak.
Bagi memudahka n doktor gigi melihat bahagian belakang gigi pesakit.
PeriSkop Kebiasaannya dijumpai di dalam almari kedai pakaian untuk memudahkan pelanggan mencuba pakaian. Cermin penuh ITeach – Fizik Tingkatan 4
Cermin pergigian
Chapter 5 Light
Understanding The Reflection Of Light Applications of of reflection reflection of of light light -- Convex Convex Mirror Mirror Applications
Rear-view mirror mirror in in Rear-view motor vehicles vehicles motor
Convex mirror mirror at at Convex road corner corner road
Anti-theft mirror mirror in in Anti-theft supermarket supermarket
To enable the driver of a motor vehicle to get a wider view of the road behind.
To enable drivers of motor vehicles to see beyond the corner.
To provide a wide view of vision of the shop.
ITeach – Physics From 4
Bab 5 Cahaya
Memahami Pantulan Cahaya Aplikasi Pantulan Pantulan Cahaya Cahaya –– Cermin Cermin Cembung Cembung Aplikasi
Cermin pandang pandang Cermin belakang pada pada belakang kenderaan kenderaan
Cermin cembung cembung di di Cermin bucu jalan jalan bucu
Cermin penggera penggera Cermin antikecurian di di Pusat Pusat antikecurian Membeli Belah Belah Membeli
Untuk memudahkan pemandu kenderaan mendapatkan gambaran yang lebih luas pada bahagian belakang kenderaan.
Untuk memudahkan pemandu kenderaan melihat jalan yang melampaui bucu jalan.
Untuk memberikan gambaran yang lebih luas di dalam kedai.
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Applications of of reflection reflection of of light light -- Concave Concave Mirror Mirror Applications
Reflector in searchlight
To produce a parallel beam of light that can shine far with high and uniform intensity.
To obtain an upright and magnified image.
Make-up mirror ITeach – Physics From 4
To focus light from distance objects into the eyepiece of the telescope. As the primary mirror in a reflection telescope
Bab 5 Cahaya
Memahami Pantulan Cahaya Aplikasi Pantulan Pantulan Cahaya Cahaya –– Cermin Cermin Cekung Cekung Aplikasi
Pemantul dalam lampu limpah
Untuk menghasilkan pancaran cahaya yang boleh memancar jauh dengan keamatan yang tinggi dan seragam.
Untuk mendapatkan imej yang tegak dan lebih besar daripada objek. Cermin solek ITeach – Fizik Tingkatan 4
Sebagai cermin utama dalam teleskop pantulan
Untuk memfokuskan cahaya daripada objek jauh ke kanta mata pada teleskop.
Chapter 5 Light
2.1 Arah Mata Angin Of Light 5.2 Understanding Refraction
ITeach – Physics Form 4
Chapter 5 Light
Understanding Refraction Of Light Refraction Of Light Refraction = Bending of the path of light Example : Refraction of light occurs at the air-glass boundary
Air
Glass
Light changes directions when it crosses the boundary from the air to the glass. When passing from air into glass, the speed and wavelength decrease.
ITeach – Physics Form 4
Bab 5 Cahaya
Memahami Pembiasan Cahaya Pembiasan Cahaya Pembiasan = Pembengkokan laluan cahaya Contoh : Pembiasan cahaya berlaku pada sempadan udara-kaca.
Air
Glass
Cahaya bertukar arah apabila ia melalui sempadan udara - kaca. Apabila cahaya bergerak dari udara ke dalam kaca, kelajuan dan jarak gelombang cahaya berkurang. ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Refraction Of Light Travelling Patterns Of Light From A Less Dense Medium To A More Dense Medium
Incident ray
air glass
Normal i
less dense more dense r
Refracted ray
The refracted light bends towards from the normal
ITeach – Physics Form 4
Bab 5 Cahaya
Memahami Pembiasan Cahaya Corak Pergerakan Cahaya Daripada Medium Kurang Tumpat ke Medium Lebih Tumpat
Sinar tuju
Udara Kaca
Normal i
Kurang tumpat Lebih tumpat r
Sinar pembiasan
Cahaya pembiasan membengkok ke arah normal
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Refraction Of Light Travelling Patterns Of Light From A More Dense Medium To A Less Dense Medium Incident ray Normal glass air
i r
more dense less dense
Refracted ray
The refracted light bends away from the normal
ITeach – Physics Form 4
Bab 5 Cahaya
Memahami Pembiasan Cahaya Corak Pergerakan Cahaya daripada Medium Lebih Tumpat ke Medium yang Kurang Tumpat Sinar tuju Normal Kaca Udara
i r
Lebih tumpat Kurang tumpat
Sinar pembiasan
Cahaya pembiasan membengkok menjauhi normal
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Refraction Of Light Travelling Patterns Of Light Perpendicularly Towards Two Mediums
Incident ray
air glass
Refracted ray
Light passed through the medium without and bending
ITeach – Physics Form 4
Bab 5 Cahaya
Memahami Pembiasan Cahaya Corak Pergerakan Cahaya Bergerak Secara Menegak Ke Arah Dua Medium
Sinar tuju
Udara Kaca
Sinar pembiasan
Cahaya melalui medium tanpa dibengkokkan.
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Refraction Of Light The Laws Of Refraction
Law 1
The incident ray and the refracted ray are on opposite side of the normal and all three are on the same plane. i
r
Law 2
ITeach – Physics Form 4
The ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant.
Bab 5 Cahaya
Memahami Pembiasan Cahaya Hukum Pembiasan
Hukum 1
Sinar tuju dan sinar pembiasan berada pada bahagian yang bertentangan daripada normal dan ketiga-tiganya berada pada satah yang sama. i
r
Hukum 2
ITeach – Fizik Tingkatan 4
Nisbah sin sudut tuju ke sin sudut pembiasan ialah pemalar.
Chapter 5 Light
Understanding Refraction Of Light Refractive Index, n (I) The angle between the incident ray and the normal is known as the angle of incidence, i.
Incident ray
The angle between the refracted ray and the normal is known as the angle of refraction, r.
air glass
Normal i
less dense more dense r Refracted ray
The refractive index of the denser medium (if the less dense medium is air) is Refractive index, n =
sin i sin r
Refractive index has no units.
Refractive index is an indicator to the “light bending ability” of a medium.
The higher the refractive index, more the light will bend when it enters the medium.
ITeach – Physics Form 4
Bab 5 Cahaya
Memahami Pembiasan Cahaya Indeks Pembiasan, n (I) Sinar tuju Sudut di antara sinar tuju dan normal dikenali sebgai sudut tuju, i. Sudut di antara sinar pembiasan dan normal dikenali sebagai sudut pembiasan, r.
Udara Kaca
Normal i
Kurang tumpat Lebih tumpat r Sinar pembiasan
Indeks pembiasan bagi medium yang lebih tumpat (jika medium yang kurang tumpat darinya ialah udara) ialah sin i Indeks pembiasan, , n = sin r
Tiada unit bagi indeks pembiasan.
Indeks pembiasan ialah penunjuk kepada “kemampuan cahaya membengkok” melalui dua medium.
Semakin tinggi indeks pembiasan, cahaya akan semakin membengkok apabila ia memasuki medium.
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Refraction Of Light Refractive Indices Of Some Common Material
ITeach – Physics Form 4
Medium
Refractive index of material, n
Air
≈ 1.0
Water
1.33 = ¾
Ice
1.31
Perspex
1.49
Diamond
2.40
Bab 5 Cahaya
Memahami Pembiasan Cahaya Indeks Pembiasan Bagi Beberapa Bahan
ITeach – Fizik Tingkatan 4
Medium
Indeks Pembiasan Bahan, n
Udara
≈ 1.0
Air
1.33 = ¾
Ais
1.31
Perspeks
1.49
Berlian
2.40
Chapter 5 Light
Understanding Refraction Of Light Determining The Refractive Index Of Glass AA monochromatic monochromatic light light ray ray is is directed directed at at an an angle angle of of incidence, incidence, ii of of 15° 15° towards towards aa piece piece of of rectangular rectangular glass glass block. block.
15° A
The The experiment experiment is is repeated repeated with with angle angle of of incidence incidence of of 20°,25°,30° 20°,25°,30° and and 35°. 35°.
AA graph graph of of sin sin ii against against sin sin rr is is plotted plotted sin i°
i° 15 20 25 30 35
B r
The The angle angle of of refraction, refraction, rr is is measured. measured.
Result Result obtained obtained
Normal
r° 23 31 40 49 60
D
C Sin i° 0.2588 0.3420 0.4226 0.5000 0.5736
Sin r° 0.3907 0.5150 0.6428 0.7547 0.8660
The The refractive refractive index index of of glass glass == gradient gradient of of the the graph graph sin r° ITeach – Physics Form 4
Bab 5 Cahaya
Memahami Pembiasan Cahaya Menentukan Indeks Pembiasan Cahaya Sinar Sinar cahaya cahaya monokrom monokrom di di tujukan tujukan pada pada sudut sudut tuju, tuju, i,i, 15° 15° ke ke arah arah sebuah sebuah bongkah bongkah kaca kaca berbentuk berbentuk segiempat segiempat tepat. tepat.
15° A
dengan dengan
Keputusan Keputusan diperolehi diperolehi Graf Graf sin sin ii melawan melawan sin sin rr diplot. diplot. sin i°
B r
Sudut Sudut pembiasan, pembiasan, rr ,, diukur. diukur. Eksperimen Eksperimen diulang diulang 20°,25°,30° 20°,25°,30° and and 35°. 35°.
Normal
i° 15 20 25 30 35
sudut sudut
tuju tuju
:: r° 23 31 40 49 60
D
C Sin i° 0.2588 0.3420 0.4226 0.5000 0.5736
Sin r° 0.3907 0.5150 0.6428 0.7547 0.8660
Indeks Indeks pembiasan pembiasan kaca kaca == Kecerunan Kecerunan graf graf sin r° ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Refraction Of Light Determining The Refractive Index Of Glass When light travels from air into glass, its speed changes as well as its wavelength.
Air
The speed of light in air is faster than the speed of light in glass. Glass
The refractive index of glass, n =
speed of light in air speed of light in glass
and also refractive index of glass, n =
ITeach – Physics Form 4
wavelength of light in air wavelength of light in glass
Bab 5 Cahaya
Memahami Pembiasan Cahaya Menentukan Indeks Pembiasan Kaca Apabila cahaya bergerak daripada udara ke dalam kaca, kelajuan dan jarak gelombang cahaya berubah.
Udara
Cahaya bergerak lebih laju di udara berbanding di dalam kaca. Kaca
Indeks pembiasan kaca,
n=
Kelajuan cahaya dalam udara Kelajuan cahaya dalam kaca
dan Indeks pembiasan kaca, n =
ITeach – Fizik Tingkatan 4
Panjang gelombang cahaya dalam udara Panjang gelombang cahaya dalam kaca
Chapter 5 Light
Understanding Refraction Of Light Real Depth And Apparent Depth
Consequences of light passing from air into water
Gives a false impression of the depth of the water.
Examples:
Refraction of light makes a swimming pool looks shallower. Refraction of light makes a stick appears bent when immersed in water. Refraction of light makes the legs of the boy in water look shorter.
ITeach – Physics Form 4
Air Water
A
P water
C
Image stone
B
Bab 5 Cahaya
Memahami Pembiasan Cahaya Dalam Nyata dan Dalam Ketara
Kesan cahaya bergerak dari udara ke dalam air
Memberikan tanggapan yang salah tentang kedalaman air.
Contoh:
Pembiasan cahaya membuatkan kolam renang kelihatan cetek. Pembiasan cahaya membuatkan batang kayu kelihatan bengkok apabila ia direndam ke dalam air. Pembiasan cahaya membuatkan kaki seorang budak kelihatan lebih pendek di dalam air.
ITeach – Fizik Tingkatan 4
Udara Air
A
P air
C
B
Imej batu
Chapter 5 Light
Understanding Refraction Of Light Refraction Index Of Water In Terms Of Real Depth And Apparent Depth Observer
B
A
Real dept, D
Air Apparent depth, d water
Real depth, D, is the distance of the object below the surface of the water. Apparent depth, d, is the distance of the image formed from the surface of the water.
Refraction Index Of Water =
ITeach – Physics Form 4
Real depth, D Apparent depth, d
Bab 5 Cahaya
Memahami Pembiasan Cahaya Indeks Pembiasan Air Dari Segi Dalam Nyata dan Dalam Ketara Pemerhati
B
A
Udara Dalam ketara, d
Dalam nyata, D
Air Dalam nyata, D, ialah jarak dari objek ke permukaan air. Dalam ketara, d, ialah jarak dari permukaan air ke imej yang terbentuk.
Indeks Pembiasan Air, n
ITeach – Fizik Tingkatan 4
=
Dalam , nyata, D Dalam ketara, d
Chapter 5 Light
5.3 Understanding Total Internal Reflection
ITeach – Physics Form 4
Chapter 5 Light
Understanding Total Internal Reflection
Critical Angle
When light travels from a denser medium (eg : glass ) into a less dense medium (eg: air), it bends away from the normal.
Normal r Air
As the angle of incidence increases, the angle of refraction also increases. When the angle of incidence increases to a certain angle, called the critical angle of glass, the refracted light will make an angle of 90° with the normal. ITeach – Physics Form 4
Glass
Incident ray
Refracted Ray Refracted Ray Refracted Ray
i=C
Bab 5 Cahaya
Memahami Pantulan Dalam Penuh
Sudut Genting Apabila cahaya bergerak dari medium lebih tumpat (cth : kaca) ke medium kurang tumpat (cth : udara), ia akan membengkok menjauhi normal.
Normal r Udara
Apabila sudut tuju bertambah, sudut pembiasan juga bertambah. Apabila sudut tuju bertambah sehingga ke suatu sudut, dipanggil sudut genting kaca, pembiasan cahaya akan membuat sudut 90° dengan normal. ITeach – Fizik Tingkatan4
Kaca
Sinar tuju
i=C
Sinar pembiasan Sinar pembiasan Sinar pembiasan
Chapter 5 Light
Understanding Total Internal Reflection happens when
Total Internal Reflection
Light travels from a more dense medium towards a less dense medium. angle of incidence > critical angle of the more dense medium. i>c
When total internal reflection occurs no light will travel into the less dense medium all light will be reflected back into the more dense medium angle of reflection, r = angle of incidence, i ITeach – Physics Form 4
Normal
Air Glass i Incident Ray
r Refracted Ray
Bab 5 Cahaya
Pantulan Dalam Penuh berlaku apabila
Pantulan Dalam Penuh
Cahaya bergerak dari medium yang lebih tumpat ke medium yang kurang tumpat. Sudut tuju > Sudut genting bagi medium yang lebih tumpat
i>c
Apabila pantulan dalam penuh berlaku tiada cahaya yang bergerak ke dalam medium kurang tumpat kesemua cahaya akan dipantulkan kembali ke medium lebih tumpat Sudut pantulan, r = Sudut tuju, i
ITeach – Fizik Tingkatan 4
Normal
Udara Kaca i Sinar tuju
r Sinar pembiasan
Chapter 5 Light
Understanding Total Internal Reflection Relationship Between The Critical Angle And Refractive Index
Light ray enters less dense medium from a more dense medium
+
Angle of refraction = 90°
angle of incidence = critical angle
sin i n= sin r
r = 90°
Air
Water i=c
ITeach – Physics Form 4
1 ° n = sin 90 = sin c sin c where c = critical angle Refractive index, n= 1 sin c
Bab 5 Cahaya
Memahami Pantulan Dalam Penuh Hubungan Antara Sudut Genting dan Indeks Pembiasan Sinar cahaya bergerak dari medium lebih tumpat memasuki medium kurang tumpat.
+
Sudut pembiasan = 90°
Sudut tuju = Sudut genting
sin i n= sin r
r = 90°
Udara Air i=c
1 ° n = sin 90 = sin c sin c Dimana, c = Sudut genting Indeks pembiasan
n = 1 sin c ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Total Internal Reflection Natural Phenomena Involving Total Internal Reflection
Mirage in a desert
ITeach – Physics Form 4
Formation of rainbow
The glitters of a diamond
Bab 5 Cahaya
Memahami Pantulan Dalam Penuh Fenomena Alam Semulajadi Melibatkan Pantulan Dalam Penuh
Pembentukan logamaya di gurun
ITeach – Fizik Tingkatan 4
Pembentukan pelangi
Gemerlapan cahaya pada berlian
Chapter 5 Light
Understanding Total Internal Reflection Application Of Total Internal Reflection
The periscope – total internal reflection occurs at A, B, C and D. P (45° A
B
Q
R
S 45°
T
)
Object O
C
D V
ITeach – Physics Form 4
Optic fibre
Prism
W
Tail-light reflector of a car
Bab 5 Cahaya
Memahami Pantulan Dalam Penuh Aplikasi Pantulan Dalam Penuh
Periskop – Pantulan dalam penuh berlaku di A, B, C dan D. P (45° A
B
Q
R
S 45°
T
)
Objek O
C
D V
ITeach – Fizik Tingkatan 4
Gentian optik
Prisma
W
Pemantul lampu belakang kereta
Chapter 5 Light
5.4 Understanding Lenses
ITeach – Physics Form 4
Chapter 5 Light
Understanding Lenses Type Of Lenses
A lens is a moulded piece of transparent material which refracts light rays to form an image. Converging lens
Diverging lens
converges rays of light travelling parallel to its principal axis. relatively thick across their middle thin at their upper and lower edges.
diverges rays of light travelling parallel to its principal axis. relatively thin across their middle thick at their upper and lower edges.
thicker across the middle thinner at its edges serves to converge light
thinner across the middle thicker at its edges serves to diverge light
ITeach – Physics Form 4
Bab 5 Cahaya
Memahami Kanta Jenis-jenis Kanta
Kanta ialah sekeping bahan lutsinar yang yang membiaskan cahaya untuk membentuk imej. Kanta menunpu
Diverging lens
Sinar cahaya menumpu bergerak selari dengan paksi utama. Tebal di bahagian tengah kanta.
Sinar cahaya mencapah bergerak selari dengan paksi utama.
Nipis di bahagian tepi atas dan tepi bawah.
Nipis di bahagian tengah. Tebal di bahagian tepi atas dan tepi bawah.
Tebal di tengah dan nipis dibahagian tepi bagi menumpukan cahaya
Nipis di tengah dan tebal di tepi bagi mencapahkan cahaya
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Lenses Anatomy Of A Lens A convex lens converges rays of light, at a point.
Parallel ray of light
Principal axis
A concave lens diverges parallel rays of light as though they originate from a point behind the lens.
F Principal axis
O
f
F
O
f
Optical centre, O
The point at the centre of the lens whereby light passes through it without any refraction.
Principal axis
The line that is drawn vertically straight towards a lens and which passes through the optical centre.
Principal focus, F
A point on the Principal axis where the rays of light parallel with Principal axis will converge after passing through a converging lens.
Focal length, f
The distance from the Principal focus to the optical centre.
ITeach – Physics Form 4
Bab 5 Cahaya
Memahami Kanta Anatomi Kanta Kanta cembung menumpu sinar cahaya pada satu titik.
Kanta cekung mencapahkan sinar-sinar cahaya selari seperti ia berasal dari satu titik di belakang kanta.
F
Sinar cahaya Paksi utama O selari
Paksi utama f
F
O
f
Pusat optik, O
Titik di tengah-tengah kanta di mana cahaya melaluinya tanpa dibiaskan.
Paksi utama
Garisan yang dilukis secara menegak lurus ke arah kanta dan melalui pusat optik.
Fokus utama, F
Satu titik di paksi utama di mana sinar cahaya yang selari dengan paksi utama akan mencapah selepas melalui kanta mencapah.
Panjang fokus, f
Jarak daripada fokus utama ke pusat optik.
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Lenses Determining The Focal Length Of A Convex Lens Distant object
Screen Convex lens
Sharp image Blur image
Almost parallel rays f Place a convex lens in front of a screen. Move the lens forwards and backwards until a sharp, inverted image of a distant object is formed on the screen. The distance from the centre of the lens to the screen is the focal length of the convex lens. ITeach – Physics From 4
Bab 5 Cahaya
Memahami Kanta Menentukan Panjang Fokus Bagi Kanta Cembung Objek jauh
Skrin Kanta cembung
Imejtajam kabur Imej
Sinar selari
f Letakkan kanta cembung di hadapan skrin. Gerakkan kanta ke hadapan dan ke belakang sehingga imej bagi objek yang jauh terbentuk tajam dan songsang pada skrin. Jarak dari tengah-tengah kanta ke skrin ialah panjang fokus bagi kanta cembung. ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Lenses Thickness Of Lens And Its Focal Length
Thickness of lens
Focal length
A thicker lens has a shorter focal length while a thinner lens has a longer focal length. To differentiate between convex lens and concave lens, convex lens : positive focal length
concave lens : negative focal length
focal length, f = -20.0 cm
refers to a concave lens of focal length of 20.0 cm
focal length, f = +10.0 cm
refers to a convex lens of focal length of 10.0 cm.
ITeach – Physics From 4
Bab 5 Cahaya
Memahami Kanta Ketebalan Kanta dan Panjang Fokus
Ketebalan kanta
Panjang fokus
Kanta yang tebal mempunyai panjang fokus yang lebih pendek manakala kanta yang nipis mempunyai panjang fokus yang lebih panjang. Untuk membezakan antara kanta cembung dan kanta cekung, Kanta cembung : Panjang fokus positif
Kanta cekung : Panjang fokus negatif
Panjang fokus, f = -20.0 cm
Merujuk kepada kanta cekung yang mempunyai panjang fokus 20.0 cm
Panjang fokus, f = +10.0 cm
Merujuk kepada kanta cembung yang mempunyai panjang fokus 10.0 cm.
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Lenses Power Of A Lens The power of a lens is defined as the reciprocal of its focal length (measured in metres)
Power of lens, P =
1 f
Unit = per metre (m-1) or the dioptre ( D ). Examples Type of lens
ITeach – Physics From 4
Focal length, f
Power, P
convex
+ 5.0 cm
1 =+ 20D + 0.05
concave
- 10.0 cm
1 =− 10D −10.0
Bab 5 Cahaya
Memahami Kanta Kuasa Kanta Kuasa kanta ditakrifkan sebagai salingan panjang fokusnya (diukur dalam meter)
Kuasa kanta, P =
1 f
Unit = per meter (m-1) atau diopter ( D ). Contoh Jenis kanta
ITeach – Fizik Tingkatan 4
Panjang fokus, f
Kuasa, P
Cembung
+ 5.0 cm
1 =+ 20D + 0.05
Cekung
- 10.0 cm
1 =− 10D −10.0
Chapter 5 Light
Understanding Lenses Steps To Take To Draw A Ray Diagram For A Convex Lens
Object
Image 2F
F
O
F
2F
Principal axis
A ray of light passes through the optical centre of the lens is undeviated. A ray of light parallel to the principal axis is refracted and passes through the principal focus, F. A ray of light which passes through F is refracted parallel to the principal axis. The point of intersection of the rays is a point on the image. ITeach – Physics From 4
Bab 5 Cahaya
Memahami Kanta Langkah-langkah Melukis Gambar Rajah Sinar Bagi Kanta Cembung
Objek
Imej 2F
F
O
F
2F
Paksi utama
Satu sinar cahaya yang bergerak melalui pusat optik kanta tidak melencong. Satu sinar cahaya selari dengan paksi utama dibiaskan dan bergerak melalui fokus utama, F. Satu sinar cahaya yang bergerak melalui F dibiaskan selari dengan paksi utama. Titik persilangan sinar-sinar cahaya ialah titik imej terbentuk. ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Lenses Steps To Take To Draw A Ray Diagram For A Concave Lens
Object 2F
F Image
O
F
2F
Principal axis
A ray of light passes through the optical centre is undeviated. A ray of light parallel to the principal axis is refracted and appears to come from the principal focus, F. A ray of light travels towards the principal focus, F is refracted parallel to the principal axis. The point of intersection of the rays is a point on the image. ITeach – Physics From 4
Bab 5 Cahaya
Memahami Kanta Langkah-langkah untuk Melukis Gambar Rajah Sinar Kanta Cekung
Objek 2F
F
O
F
2F
Paksi utama
Imej
Satu sinar cahaya yang bergerak melalui pusat optik tidak melencong. Satu sinar cahaya yang selari dengan paksi utama dibiaskan dan kelihatan seperti bergerak dari fokus utama, F. Satu sinar cahaya bergerak ke arah fokus utama, F dibiaskan selari dengan paksi utama. Titik persilangan sinar-sinar cahaya ialah titik pada imej. ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Image Formed By A Convex Lens For An Object At Infiniti Light ray from the object
F Image v
Image distance, v = f
inverted
real
reduced in size
ITeach – Physics From 4
Bab 5 Cahaya
Memahami Kanta Imej yang Dibentuk Oleh Kanta Cembung Bagi Objek Di Infiniti Sinar cahaya dari objek
F Imej v
Jarak imej, v = f
Songsang
Nyata
Lebih kecil dari objek
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Image Formed By A Convex Lens For An Object Further Than 2f , u > 2f
Object
Image 2F
F
u
F
2F
v
Image distance, f < v < 2f
inverted
real
reduced in size
ITeach – Physics From 4
Bab 5 Cahaya
Memahami Pantulan Cahaya Imej yang Dibentuk Oleh Kanta Cembung Bagi Objek Melampaui 2F, u > 2f
Objek
Imej 2F
F
u
F
2F
v
Jarak imej, f < v < 2f
Songsang
Nyata
Lebih kecil daripada objek
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Image Formed By A Convex Lens For An Object At 2f , u = 2f
Object 2F
F
F
u
v
2F Image
Image distance, v = 2f
inverted
real
same size with object
ITeach – Physics From 4
Chapter 5 Light
Understanding The Reflection Of Light Imej yang Dibentuk Oleh Kanta Cembung Bagi Objek Di 2f, u = 2f
Objek 2F
F
F
u
v
2F Imej
Jarak imej, v = 2f
Songsang
Nyata
Sama saiz dengan objek
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Image Formed By A Convex Lens For An Object Between f and 2f, f < u < 2f
Object 2F
F
F
u
2F
v
Image distance, v > 2f
inverted
real
magnified
ITeach – Physics From 4
Image
Chapter 5 Light
Understanding The Reflection Of Light Imej yang Dibentuk Oleh Kanta Cembung Bagi Objek Di Antara f dan 2f, f < u < 2f
Objek 2F
F
F
u
2F
Imej
v
Jarak imej, v > 2f
Songsang
Nyata
Lebih besar daripada objek
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Image Formed By A Convex Lens For An Object At f, u = f
Object
O F
F
To infinity
Image distance, v at infinity
upright
virtual
magnified
ITeach – Physics From 4
Bab 5 Cahaya
Memahami Kanta Imej yang Dibentuk Oleh Kanta Cembung Bagi Objek Di F, u=f
Objek
O F
F
Ke infiniti
Jarak imej, v di infiniti
Tegak
Maya
Lebih besar daripada objek
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding The Reflection Of Light Image Formed By A Convex Lens For An Object Between f And The Lens, u < f
Image Object F
u
F
v
Image distance, v > f
upright
virtual
magnified
ITeach – Physics From 4
Bab 5 Cahaya
Memahami Kanta Imej yang Dibentuk Oleh Kanta Cembung Bagi Objek Di Antara F dan Kanta, u < f
Imej Objek F
u
F
v
Jarak imej, v > f
Tegak
Maya
Lebih besar daripada objek
ITeach – Fizik Tingkatan 4
Chapter 5 Light
Understanding Lenses Image Image Formed Formed By By A A Concave Concave Lens Lens The characteristics of the image formed by a concave lens does not depend on the location of the object. Object
O
F
Image
Image formed by a concave lens is always
virtual ITeach â&#x20AC;&#x201C; Physics From 4
upright
between the object and the lens
smaller than the size if the object
Bab 5 Cahaya
Memahami Kanta Imej Imej yang yang Dibentuk Dibentuk Oleh Oleh Kanta Kanta Cekung Cekung Ciri-ciri imej yang dibentuk oleh kanta cekung tidak bergantung kepada kedudukan objek. Objek
O
F
Imej
Imej yang dibentuk oleh kanta cekung sentiasa
Maya ITeach â&#x20AC;&#x201C; Fizik Tingkatan 4
Tegak
Di antara objek dan kanta
Lebih kecil daripada saiz objek
Chapter 5 Light
Understanding Lenses Linear Magnification Linear magnification is the ratio of the size of the image formed to the size of the object. Object ho
I
2F O
F
2F
F
hI u
Linear magnification, m =
Linear magnification, m = ITeach â&#x20AC;&#x201C; Physics From 4
v
Height of image, hI Height of object, hO Image distance, v Object distance, u
Bab 5 Cahaya
Memahami Kanta Pembesaran Linear Pembesaran linear ialah nisbah saiz imej ke saiz objek. Objek ho
I
2F O
F
2F
F
hI u
Pembesaran linear, m =
Pembesaran linear, m = ITeach â&#x20AC;&#x201C; Fizik Tingkatan 4
v
Tinggi imej, hI Tinggi objek, hO Jarak imej, v Jarak objek, u
Chapter 5 Light
Understanding Lenses The Lens Equation Lens equation shows the relationship between object distance, u, image distance, v, and the focal length of a lens, f.
1 1 1 + = u v f
Where u = object distance v = image distance f = focal length applicable for both convex lens and concave lens. When using the lens equation for a convex lens, the focal length, f, takes a positive value. When using the lens equation for a concave lens, the focal length, f, takes a negative value. ITeach â&#x20AC;&#x201C; Physics From 4
Bab 5 Cahaya
Memahami Kanta Persamaan Kanta Persamaan kanta menunjukkan hubungan antara jarak objek, u, jarak imej, v, dan panjang fokus kanta, f.
1 1 1 + = u v f
Di mana u = jarak objek v = jarak imej f = panjang fokus Digunakan untuk kanta cembung dan kanta cekung. Apabila persamaan kanta digunakan untuk kanta cembung, panjang fokus, f, mengambil nilai positif. Apabila persamaan kanta digunakan untuk kanta cekung, panjang fokus, f, mengambil nilai negatif. ITeach â&#x20AC;&#x201C; Fizik Tingkatan 4
Chapter 5 Light
Understanding Lenses Graphical Analysis For Convex Lens
Graph of v against u v
Graph of uv against (u + v) uv v=u
S (2f, 2f) gradient = f u
o Graph of v against m v
o Graph of u against l/m u
gradient = f
gradient = f f
f o ITeach â&#x20AC;&#x201C; Physics From 4
(u + v)
m
o
l m
Bab 5 Cahaya
Memahami Kanta Analisis Graf Bagi Kanta Cembung
Graf v melawan u v
Graf uv melawan (u + v) uv v=u S (2f, 2f) kecerunan= f u
o Graf v melawan m v
o Graf u melawan l/m u
kecerunan = f
kecerunan = f f
f o ITeach â&#x20AC;&#x201C; Fizik Tingkatan 4
(u + v)
m
o
l m
Chapter 5 Light
Understanding Lenses Optical Devices
Magnifying glass
Eyeglasses
Camera ITeach â&#x20AC;&#x201C; Physics From 4
Bab 5 Cahaya
Memahami Kanta Alat â&#x20AC;&#x201C; alat Optik
Kanta pembesar
Cermin mata
Penutup
Bukaan
Kamera ITeach â&#x20AC;&#x201C; Fizik Tingkatan 4
Kanta
Filem
Chapter 5 Light
Understanding Lenses
Body Tube
The Compound Microscope eyepiece
objective
f0 I object Revolving 2 fNosepiece 0 Objectives h2 u > f0 Stage Clips Diaphragm
construction ray
I1
fe
Ocular Lens (Eyepiece)
Arm
h1
D = 25 cm How A Microscope Works
Stage Coarse Adjustment Knob
Lightobject Source Fine The is placed between f0 and 2f0 in front of the objective lens. Adjustment Knob The first image becomes the object for the eyepiece lens. Base The first image is formed less than fe in front of the eyepiece lens so that the final image formed is virtual, magnified and at a distance of 25cm from eyepiece lens. ITeach â&#x20AC;&#x201C; Physics From 4
Bab 5 Cahaya
Memahami Kanta Mikroskop Majmuk
Tiub badan
Kanta okular (Kanta mata)
Kanta mata
Sinar pembentukan
Kanta objek
f0 I objek Pemutar kanta 2 f0 objektif Kanta objektif h2 u > f0 Klip pentas Diafragma
I1
fe
Lengan
h1
D = 25 cm Bagaimana Mikroskop Berfungsi?
Pentas Pelaras kasar
Sumber cahaya di antara f dan 2f di hadapan kanta objek.Pelaras halus Objek diletakkan 0 0 Imej yang pertama dibentuk oleh kanta objek bertindak sebagai objek bagi kanta mata. Tapak Imej yang pertama terbentuk kurang daripada fe di hadapan kanta mata supaya imej akhir yang terbentuk adalah maya, lebih besar daripada objek dan pada jarak 25 cm daripada kanta mata. ITeach â&#x20AC;&#x201C; Fizik Tingkatan 4
Chapter 5 Light
Understanding Lenses The Astronomical Telescope Objective lens (convex)
Eyepiece lens
Light
Telescope tube
objective
final image at infinity ITeach â&#x20AC;&#x201C; Physics From 4
construction ray eyepiece
Information
Bab 5 Cahaya
Memahami Kanta Teleskop Astronomi Kanta objek (cembung)
Kanta mata
Cahaya
Tiub teleskop
Sinar pembentukan Kanta objek
Imej akhir di infiniti ITeach â&#x20AC;&#x201C; Fizik Tingkatan 4
Kanta mata
Maklumat
The End
i - Teach