3. Diagram
3.1shows an object in front of a bulb. The object is 10 cm from the convex
lens. A screen is placed behind the lens and the distance is adjusted until a
sharp image is formed on the screen. The distance between the object and the
lens is then increased as shown by diagram 3.2. The image formed on the screen
in diagram 3.2 is smaller than in diagram 3.1.
Rajah 3.1 menunjukkan satu objek di hadapan satu mentol. Objek itu
berada 10 cm dari kanta cembung. Satu skrin diletakkan di belakang kanta dan jaraknya dilaraskan sehingga
satu imej yang tajam terbentuk. Jarak antara objek dan kanta kemudian ditambah
seperti yang ditunjukkan dalam rajah 3.2. Imej yang terbentuk di atas skrin
dalam rajah 3.2 lebih kecil dari rajah 3.1.
Based on the
information and observation above:
Berdasarkan maklumat dan pemerhatian di atas:
(a) State one suitable inference [1 mark] Nyatakan
satu inferens yang sesuai
The object distance affects the
size of the image
(b) State one suitable hypothesis
Nyatakan satu
hipotesis yang sesuai
The greater the object distance, the smaller the size of
the image
[1
mark]
(c) With the use of
apparatus such as convex lens and other suitable
apparatus, describe an experiment framework to investigate the hypothesis
stated in 3 (b). In your description, state clearly the following:
Dengan menggunakan radas seperti kanta cembung dan
radas lain yang sesuai, huraikan satu
rangka eksperimen untuk mengkaji hipotesis yang dinyatakan di 3 (b).
Didalam penerangan anda,
nyatakan dengan jelas yang berikut:
(i) Aim of the
experiment
Tujuan eksperimen
To investigate the relationship between the object
distance and the size of the image
(ii) Variables in the
experiment
Pemboleubah di dalam eksperimen
Manipulated variable : object distance, u
Responding
variable : size of the image, H
State the fixed variable
Focal
length of the lens / type of lens
(iii) List of apparatus
and materials
Senarai radas dan bahan
Convex
lens with holder, light bulb with power supply, screen, metre rule
(iv) Arrangement of the
apparatus
Susunan radas
Light bulb in holder connected to power supply// Cross-wire
as the object in front of the bulb, convex lens in holder and screen – all
align.
(v) The
procedure of the experiment which include the method of controlling the
manipulated variable and the method of measuring the responding variable.
Prosedur eksperimen yang meliputi kaedah untuk
mengawal pembolehubah manipulasi dan kaedah untuk mengukur
pembolehubad bergerak balas.
The
convex lens is placed at distance of, u
= 15 cm from the object
The screen is adjusted until a sharp image is formed on it.
The
size of the image, H is measured.
The
procedure is repeated with values of u
= 20 cm, 25 cm, 30 cm, 35 cm and 40 cm.
(vi) The way you would tabulate
the data
Kaedah untuk menjadual data
|
u / cm
|
H / cm
|
|
15
|
|
|
20
|
|
|
25
|
|
|
30
|
|
|
35
|
|
|
40
|
|
(vii) The way you would analyze the data Kaedah
untuk menganalisis data
[10
marks]
A graph of H against u is drawn