9.1

1

9.1

Rajah 9.1.1 / Diagram 9.1.1 2. Apa yang berlaku kepada tenaga elektron jika
logam dipanaskan?
Rajah 9.1.1 menunjukkan denyutan jantung seorang What happen to the energy of the electron if the
pesakit di hospital boleh diawasi menggunaka alat metal is heated?
dikenali sebagai osiloskop sinar katod. Ia berkerja
dengan membebaskan elektron daripada pross ………………………………………………………………
yang dikenali sebagai pancaran termion.
The heart beats of a patient in a hospital can be 3. Apa yang berlaku kepada elektron bebas jika
monitored by using a device called cathode ray logam dipanaskan pada suhu yang tinggi?
oscilloscope. It works by emitting electrons from the What happens to the free electrons if the metal is
process called thermionic emission. heated at a high temperature?

Aktiviti 1 / Activity 1 ………………………………………………………………
Tujuan: Menerangkan pancaran termion
Aim: Explain thermionic emission ………………………………………………………………

4. Apakah nama diberikan kepada proses yang
membebaskan elektron?
What is the name of this process of electrons
emission?

………………………………………………………………

5. Apa maksud pancaran termion?
What is thermionic emission?

1. Permukaan logam mengandungi bilangan Aktiviti 2 / Activity 2
elektron bebas yang banyak. Apakah elektron Tujuan: Menerangkan sinar katod
bebas? Aim: Explain cathode rays
The surface of metal contains a large number of
free electrons. What are free electrons? Rajah 9.1.3 menunjukkan satu tiub vakum.
Diagram 9.1.3 shows a vaccum tube.
• Logam mempunyai bilangan ………………. yang 1. Apakah itu tiub vakum?

banyak yang bebas bergerak. What is a vacuum tube?
………………………………………………………………
Metal consists of a large number of ………….. ………………………………………………………………

which are free to move.

• Pada suhu bilik, elektron-elektron adalah
……….. bergerak tetapi tetap berada di dalam
logam.
At room temperature, the electrons are …………..

to move but remain inside the metal.

• Elektron-elektron tidak boleh lepas daripada
permukaan sebab mereka ditarik oleh ………..

tarikan nuklues atom.

The electrons cannot escape at the surface

because they are held back by the attractive

________ of the atomic nucleus.

2

2. Nyatakan sambungan terminal yang betul untuk (a) Apakah senapang elektron?
katod dan anod. What is an electron gun?
State the correct terminal connection for anode and
cathode. ………………………………………………………………

……………………………………………………………… ………………………………………………………………
………………………………………………………………
(b) Dengan melengkapkan jadual di bawah,
3. Apa yang berlaku kepada penunjuk miliammter huraikan prinsip kerja senapang elektron.
jika anda menekankan suis bekalan kuasa 6 V,S1 By completing the table below, explain the working
What happens to the miliammeter pointer if you click principle of an elektron gun.
the 6 V power supply switch, S1?
Struktur Fungsi
……………………………………………………………… Sturctue function

4. Ini menandakan apa? 6 V a.u
What does this indicate? 6 V a.c

……………………………………………………………… Filamen / katod
Filament /
5. Tekan suis S1 dan S2 (EHT power supply). Apa cathode
yang berlaku kepada bacaan miliammter. Click
switch S1 and S2 (the EHT switch). What happens to Anod
the miliammeter reading? Anode

……………………………………………………………… Voltan lampau
tinggi,
6. Ini menandakan apa Extra high tension
What does this indicate?
Skrin
……………………………………………………………… berpendaflour
Pendarflour
7. Terangkan jawapan anda di soalan 6. screen
Explain your answer in question 6.
(c) Mengapakah ruang dalam senapang elektron
……………………………………………………………… divakumkan?
……………………………………………………………… Why the space in the electron gun is vacuumed?
………………………………………………………………
……………………………………………………………… ………………………………………………………………

8. Apakah itu sinar katod? ………………………………………………………………
What is cathode rays?
Eksperimen 1 / Experiment 1:
9. Rajah 9.1.4 menunjukkan satu senapang Tujuan: Mengkaji ciri-ciri sinar katod menggunakan
elektron.
Diagram 9.1.4 shows an electron gun. tiub Palang Maltese
Aim: Investigate the properties of electron streams

in a Maltese cross cathode ray tube.

Radas: Tiub Palang Maltese, bekalan kuasa Voltan
lampau tinggi, VLT, wayar penyambung,
magnet

Apparatus: Maltese cross tube, Extra Hight Tension
(E.H.T) power supply, connecting wires, a
strong magnet

Prosedur / Procedure 3
1. 6 V bekalan pemanas dihidupkan.
Prosedur / Procedure
6 V heater supply is connected 3. Bekalan pemanas 6 V dan bekalan voltan
Pemerhatian / Observation:
……………………………………………………………… lampau tinggi 3 kV disambungkan. Dua magnet
……………………………………………………………… bar diletakkan di tepi tiub.
Penerangan / Explanation: 6 V heater supply and 3 kV power supply are
...................................................................................... connected. Two bar magnets are placed by sides
……………………………………………………………… of the tube.
………………………………………………………………
Kesimpulan / Conclusion: Pemerhatian / Observation:
......................................................................................
Prosedure / Procedure ………………………………………………………………
2. 6 V bekalan pemanas dan bekalan kuasa 3 kV
Penerangan / Explanation:
VLT dihidupkan.
6 V heater supply and 3 kV power supply are ......................................................................................
connected ………………………………………………………………
Pemerhatian / Observation:
……………………………………………………………… Kesimpulan / Conclusion:
………………………………………………………………
......................................................................................
Penerangan / Explanation:
...................................................................................... Namakan peraturan yang digunakan untuk
…………………………………………………………….. menentukan arah pesongan bayang.
Kesimpulan / Conclusion: Name the rule used to determine the direction of
1. ................................................................................ deflection of the shadow between the magnetic fields.
2. ………………………………………………………… ………………………………………………………………
3. …………………………………………………………
Eksperimen 2 / Experiment 2:
………………………………………………………… Tujuan: Mengkaji ciri-ciri sinar katod di dalam

medan elektrik menggunakan tiub
pemesongan sinar katod.
Aim: Investigate the properties of cathode rays in an
electric field by using a defleting cathode ray
tube.

Prosedur / Procedure 4

1. Sambungkan tiub pemesongan sinar katod ke 2. Nyatakan jenis tenaga dan pergerakan sinar
katod dalam tiub sinar katod.
bekalan kuasa 6.0 V a.u Types of energy and motion of the cathode rays in a
cathode rays tube
Connect the deflecting cathode ray tube to the 6.0

V ac power supply

Prosedur Pemerhatian

procedure observation

Sambungkan anod dan

katod ke bekalan kuasa

VLT 1.

Connect the anode and

cathode to EHT 1 power

supply.

Sambungkan plat kawasan Jenis pergerakan
pemesongan Region Types of Motion
menggunakan VLT 2. Plat PQ : Katod ke Anod
atas disambungkan ke Cathode to Anode
terminal positif EHT 2 dan
plat bawah QR: anod ke skrin
disambungkan ke Anode to screen
terminal negatif.
Connect the deflecting Kawasan / Region Jenis tenaga
plates using a separate Types of energy
EHT 2. Top plate is P : Katod
connected to the positive Cathode
EHT 2 and lower plate is
connected to the negative PQR: katod ke skrin
terminal EHT. cathode to screen

Ulang eksperimen dengan R : skrin
plat atas disambungkan screen
ke terminal negatif EHT 2
dan plat bawah 3. Namakan tenaga yang dibekalkan kepada sinar
disambungkan ke katod oleh bekalan kuasa VLT di antara katod
terminal positif. dengan anod.
Repeat the experiment by Name the energy which is supplied to the cathode
connecting top plate to the rays by the power supply EHT between cathode and
negative EHT2 and lower anode.
plate is connected to the
positive terminal EHT. ………………………………………………………………

Kesimpulan / Conclusion: 4. Diberi Q = e, cas 1 elektron 1.6 x 10-19 C , V =
1. ………………………………………………………… beza keupayaan merentasi katod dengan anod.
2. ………………………………………………………… Tulis satu persamaan yang menghubungkan
antara tenaga, E, e dan V.
Aktiviti 3 / Activity 3: Given that Q = e, cas for 1 electron, 1.6 x 10-19 C
1. Huraikan ciri-ciri sinar katod and V = voltage across cathode and anode. Write
an equation to relate between the energy, E, e and
Describe the properties of cathode rays V.

1. ………………………………………………………… ………………………………………………………………

2. ………………………………………………………… 5. Namakan tenaga yang diperolehi oleh elektron
apabila ia memecut daripada katod menuju ke
3. ………………………………………………………… skrin.
Name the energy gains by the electron when it
4. ………………………………………………………… accelerates from cathode to the screen.

5. ………………………………………………………… ………………………………………………………………

………………………………………………………… 6. Diberi m = jisim elektron, v = laju elekron, tulis
persamaan yang menghubungkan tenaga, E ,
m dan v.
Given that m = mass of electron, v = speed of
electron, write an equation to relate energy, E, m
and v.

7. Tenaga dalam soalan 3 akan dipindahkan 5
kepada tenaga dalam soalan 5. Namakan
prinsip fizik yang menghubungkan antara 3. Graf yang dihasilkan pada OSK terdiri
kedua-dua tenaga ini. daripada 2 paksi.
Energy in question 3 is transferred to energy in The graph produced in CRO consists of 2 axises.
question 5. State the physics principle which Menegak (paks y) / Vertical (y-axis):
relates these enegies. ……………………………………………………
Mengufuk (paksi x) / Horizontal (x-axis):
……………………………………………………………… ……………………………………………………

8. Tulis persamaan yang menghubungkan kedua- 4. Namakan 3 komponen dalam OSK.
dua tenaga mengikut prinsip yang dinyatakan Name 3 components in CRO.
dalam soalan 7. Write an equation to relate both
energies based on the principle stated in question 1. …………………………………………………
7. 2. …………………………………………………
3. …………………………………………………
……………………………………………………………… 5. Nyatakan fungsi senapang elektron dalam

9. Nyatakan perubahan tenaga yang diperolehi OSK.
oleh elektron daripada katod ke skrin. State the function of an electron gun in CRO.
State the energy changes gains by the electron …………………………………………………………….
from cathode to the screen. …………………………………………………………….
Lengkapkan jadual di bawah. Rujuk Rajah 9.1.9.
……………………………………………………………… Complete table below. Refer to Diagram 9.1.9.

10. Beza keupayaan antara katod dengan anod

ialah 3000 V. Cas satu elektron ialan 1.6

x 10-19 C. Hitung tenaga kinetik yang diperolehi

oleh elektron ketika ia sampai di anod.

The voltage between the cathode and anode is

3000 V. The charge of an electron is 1.6 x 10-19 C.

Calculate the kinetic energy possesses by an

electron as it reaches the anode.

11. Jika beze keupayaan yang merentasi katod
dan anod sebuah tiub vakum ialah 4 500 V,
berapakah laju elektron ketika sampai di anod
tiub vakum itu?
If the voltage across cathode and anode in a
vacuum tube is 4 500 V, what is the speed of
elektron as it reaches the anode?
(e = 1.6 x 10-19 C, m = 9.1 x 10-31 kg)

Aktiviti 4 / Activity 4
Tujuan: Huraikan Osiloskop sinar katod
Aim: Describe the Cathode Ray Oscilloscope

1. Apa itu osiloskop sinar katod (O.S.K)?
What is a cathode ray oscilloscope (C.R.O?)

………………………………………………………

………………………………………………………

2. Nyatakan 3 kegunaan OSK.
State 3 usage of CRO.

1. …………………………………………………

2. …………………………………………………

3. …………………………………………………

6

Struktur Fungsi ………………………………………………………..
structure Function
Dipanaskan apabila arus melaluinya. Ia (c) Apa yang berlaku kepada alur elektron dan
digunakan untuk memanaskan katod. di mana kedudukan tompok cerah apabila beza
Is heated when current flows through it. It keupayaan negatif input dikenakan?
is used to heat up the cathode. What happens to the electron beam and the
position of the bright spot when a negative voltage
Katod yang dipanaskan membebaskan is applied?
elektron melalui proses pancaran ………………………………………………………..
termion ………………………………………………………..
Heated cathode emits electrons through
the process of thermionic emissions.
Mengawal bilangan elektron dalam alur
elektron.
Control the number of electrons in the
electron beams.
Memfokus elektron kepada satu satu
alur halus supaya satu tompok cahaya
tajam akan terbentuk pada skrin.
To focus the electrons into a fine beam so
that a sharp light spot is produced on a
screen.

Memecutkan alur elektron ke arah
skrin.
To accelerate the electron beam towards
the screen.

6. Nyatakan fungsi sistem pemesongan sebuah OSK. (d) Apa yang berlaku kepada alur elektron dan di
State the function of a deflecting system in a CRO mana kedudukan tompok cerah apabila beza
……………………………………………………………… keupayaan arus ulang alik dikenakan?
……………………………………………………………… What happens to the electron beam and the
Plat Y / Y-plates: ………………………………………… position of the bright spot when an a.c voltage is
……………………………………………………………… applied?
Plat X / X-plates: ………………………………………...
……………………………………………………………… ………………………………………………………..

………………………………………………………..

……………………………………………………….

(a) Apa yang berlaku kepada alur elektron dan di (7) Terangkan bagaimana tompok cerah
mana kedudukan tompok cerah apabila tidak dihasilkan atas skrin sebuah OSK.
ada beza keupayaan input dikenakan? Explain how the bright spot is formed on the
What happens to the electron beam and the screen of the C.R.O.
position of the bright spot when no input voltage is
applied? …………………………………………...................

………………………………………………………..

………………………………………………………..

............................................................................

...........................................................................

(b) Apa yang berlaku kepada alur elektron dan di
mana kedudukan tompok cerah apabila beza
keupayaan positif input dikenakan?
What happens to the electron beam and the
position of the bright spot when a positive voltage
is applied?

………………………………………………………..

7

Hurai prinsip kerja osiloskop sinar katod Tutup Dasar-masa / Turn off time base
Describe the working principle of the cathode ray
oscilloscope CRO

Sambungan ke bateri Terbalikkan sambungan
Connected to a dry cell Reversed the dry cell
connection

Buka Dasar-masa / Turn on time base

Aktiviti 5 / Activity 5
Tujuan: Paparan bentuk gelombang
Aim: Displaying waveforms

1. Setkan gandaan-Y OSK kepada 0.5 V/bahagian. Sambungan ke bateri Terbalikkan sambungan
Tutup suis dasar-masa. Connected to a dry cell Reversed the dry cell
Set the Y-gain of the CRO to 0.5 V/div.Turn off the
time base. connection

2. Sambungkan bateri ke input-Y. 7. Sambungkan bekalan kuasa 2 V a.u ke input Y.
Connect a battery to the Y-input Connect an AC current of 2 V to the Y-input

3. Perhatikan paparan OSK pada skrin. 8. Perhatikan paparan atas skrin.
Observe the display on the CRO screen. Observe the display on the screen

4. Terbalikkan terminal bateri. Ulang langkah 3. Pemerhatian / Observation:
Reverse the terminals of the battery. Repeat step 4.
Tutup dasar-masa Buka dasar-masa
5. Hidupkan dasar-masa. Perhatikan paparan pada Turn off time base Turn on time base
skrin OSK.
Turn on the time base. Observe the display on the
CRO screen.

6. Terbalikkan terminal bateri dan perhatikan
semula.
Reverse the terminals of the battery and observe
again

Pemerhatian / Observation

Tiada input / No input

Aktiviti 6 / Activity 6: 8
Tujuan: Mengukur beza keupayaan menggunakan
Apakah perubahan pada paparan skrin apabila
OSK. dasar-masa dibuka?
Aim: Measure Potential Difference using the C.R.O What is the difference in the display when the time base
is turned on?
1. Beza keupayaan a.t. dengan dasar-masa ditutup
d.c voltage with the time-base off ………………………………………………………………

Berapakah nilai beza keupayaan a.t. dalam Rajah 3. Beza keupayaan a.u dengan dasar-masa dibuka
AC voltages with the time-base on:

9.1.13(a) dan 9.1.13(b) jika gandaan-Y ialah 1

V/bahagian.

What is the value of the dc voltage in Diagram 9.1.13(a)

and 9.1.13(b) if the Y-gain control is 1 V/div?

…………………………. ………………………… Gandaan Y = 2 V/bahagian / Y-gain = 2 V/div
Tinggi garis menegak daripada kosong = …………
2. Beza keupayaan a.t dengan dasar-masa dibuka Height of vertical trace from zero position = ………….
DC voltages with the time-base on:
Beza keupayaan a.u puncak = …………………
Berapakah nilai beza keupayaan a.t. dalam Rajah Peak ac voltage = ………………………
9.1.14(a) dan 9.1.14(b) jika gandaan-Y ialah 0.5
V/bahagian? Apa perubahan pada paparan skrin jika beza
What is the value of the dc voltage in Diagram 9.1.14(a) keupayaan a.u input digandakan?
and 9.1.14(b) if the Y-gain control is 0.5 V/div? What is the change in the screen display if the input AC
voltage is doubled?
…………………. ……………………
………………………………………………………………
Apakah perubahan yang diperhatikan atas skrin
apabila terminal bateri diterbalikkan? Apa berlaku kepada paparan atas skirn jika
What difference can be observed on the screen when gandaan Y dikurangkan ke 0.5 V/bahagian?
the terminals of a battery are reversed? What happen to the display on the screen if the Y-gain
is decreased to 0.5 V/div?
………………………………………………………………
………………………………………………………………
Apabila dua bateri disambung sesiri digunakan,
apakah perubahan yang boleh diperhatikan atas Aktiviti 7/ Activity 7:
skrin? Tujuan; Mengukur sela masa pendek menggunakan
When two batteries in series are used, what difference O.S.K
can be observed on the screen? Aim: Measure Short Time Intervals using the

…………………………………………………………….. C.R.O

1. Dasar-masa disetkan ke 1 ms/bahagian; 1
bah. = 0.001 s.
The time-base is set to 1 ms/div;it means I div =
0.001 s

2. Bilangan bahagian dikira antara dua puncak.
The number of div is counted between two crests.

3. Sela masa pendek antara dua denyutan = bil.
Bahagian x dasar-masa.
The short time interval between pulses =
Multiplying the number of division by the time-base

4. Panjang antara 2 isyarat = ………….. bah.
Length between 2 signals = ……….. div

Masa diambil = ……………….. 9
Time taken, t = …………………
3. Rajah 9.1.19 menunjukkan gelombang
Latihan / Exercise dihasilkan oleh penjana audio yang dipaparkan
Selesaikan masalah berkaitan paparan O.S.K. pada OSK. Panjang antara dua puncak ialah 3
Solve Problems based on the C.R.O display cm.
Diagram 9.1.19 shows a wave produced by an
1. Rajah 9.1.17 menunjukkan satu surih dihasilkan audio generator displayed the screen of a CRO.
oleh bekalan kuasa a.u yang disambung ke The length between the two crests is 3 cm.
input-Y OSK yang disetkan pada 20 V/bah dan 5 (a) Jika dasar-masa disetkan ke 5 ms/bah, cari
ms/bah. tempoh gelombang.
Diagram 9.1.17 shows a trace produced by an ac If the time-base is set to 5 ms/div, find the
power supply which is connected to Y-input of an period of the wave.
CRO setting at 20 V/div and 5 ms/div. (b) Berapakah frekuensi gelombang?
What is the frequency of the wave?
(c) Apabila frekuensi gelombang
digandaduakan, berapakah panjang antara
dua puncak?
When the frequency of the wave is double,
what is the length between the two crests?

Hitung / Calculate: 4. Rajah 9.1.20 menunjukkan satu gelombang
(a) Tempoh / Period dipaparkan pada skrin OSK apabila bekalan
kuasa a.u disambung ke input-Y OSK.
(b) Frekuensi / Frequency Berapakah beza keupayaan puncak apabila
gandaan-Y dilaraskan ke 20 V/cm?
(c) Beza keupayaan puncak / Peak voltage Diagram 9.1.20 shows a waveform is displayed on
the screen of a CRO when an a.c. power l is
2. Rajah 9.1.18 menunjukkan satu surih dihasilkan connected to Y-input of the CRO . What is the peak
oleh bekalan kuasa a.u yang disambungkan ke voltage of the alternating current when the Y-gain of
OSK dengan dasar-masa ditutup. Gandaan-Y the CRO is adjusted at 20 V cm-1?
diset ke 20 V/bah. Cari beza keupayaan puncak.
Diagram 9.1.18 shows a trace produced by an a.c 5. Satu kapal terbang dikesan daripada sebuah
power supply connected to a CRO with the time stesyen radar. Kedua-dua isyarat Y yang
base is switched of. The Y-gain is set to 20 V/div. dipancarkan dan isyarat X yang dipantulkan
Find the peak voltage. dipaparkan pada skrin OSK seperti
ditunjukkan dalam Rajah 9.1.20. Dasar-masa
diset pada 50 ms/bah dan laju isyarat di
udara ialah 3 x 108 ms-1. Hitung jarak antara
kapal terbang dengan stesen radar pada
ketika itu.
An aircraft is detected from a radar station. The
two transmitted signal Y and reflected signal, X
are displayed on the screen of a CRO as shown
in Diagram 9.1.20. The time-base is set at 50
ms/div and the speed of the signal in air is 3 x
108 ms-1 .
Calculate the distance of the aircraft detected
from the radar station at that time.

10

3. The diagram shows a waveform is displayed on
the screen of a CRO when an a.c. power l is
connected to Y-input of the CRO .The time-base
is switched off

TUTORIAL 9.1 What is the peak voltage of the alternating
current when the Y-gain of the CRO is adjusted
1. Which diagram shows the correct movement of at 20 V cm-1?
an electron beam in an electric field? (2005)
A 80.0 V
B 56.6 V
C 40.0 V
D 28.3 V
E 15.9 V

4. The diagram shows a waveform is displayed on
the screen of a CRO when a moving an a.c.
power supply is connected to Y-input of the
CRO. The frequency of the alternating current
is 200 Hz.

2. The diagram shows the trace on the of a CRO What is the time taken from A to B?
when an a.c. power supply is connected to the A 5 x 10 -3 s
Y-input of the CRO. B 7.5 x10 -3 s
C 1.0 x 10 -2 s
Which of the following tracing is formed on the D 5.0 x 10-2 s
screen when the a.c. power supply is replaced
by a dry cell? 5. The figure shows a waveform obtained on the
screen of CRO at an airport radar station. The
point M and N indicate the time transmission to
an aero plane and time of receiving the
reflected signals by the radar station .
[ Time-base control setting of the CRO = 5 ms
cm-1 , the speed of light = 3 x 10 8 m s -1

What is the distance between the radar station
and the aero plane.
A 600 km
B 1500 km
C 300 km
D 100 km

6. Diagram 27 shows a cathode being heated by a 11
filament.
9. Diagram 29 shows a shadow formed on the
screen of a Maltese Cross Tube. The shadow is
deflected by the magnets.

Which particle is emitted from the cathode? The direction of the deflection is determined by
(2008) using (2011)
A. proton A. The Fleming’s left hand rule
B. neutron B. The Fleming’s right hand rule
C. electron C. The right hand grip rule
D. alpha
10. Diagram 33 shows the structure of a cathode
7. Diagram 26 shows an audio signal generator ray oscilloscope.
connected to a cathode ray oscilloscope, CRO.

Which signal shows the loudest and the Which component A, B, C and D causes the
highest pitched audio signal. (2009) electrons to accelerate? (2011)

8. Diagram 15 shows the process of electrons 11. Which particle escapes from the surface of a
escaping from the surface of a heated metal. metal when it is heated at a high temperature?
(2012)
A. Proton
B. Neutron
C. Nucleon
D. Electron

PAPER 2, SECTION A

1. Question 4: Melaka 09
Diagram 4.1 shows a deflecting cathode rays tube

What is this process? (2011)

A. Radiation C. Rectification

B. Evaporation D. Thermionic Emission

(a) The function of the filament is to heat the
cathode and releases electrons on its surface

(i) Name the process mention in (a)

……………………………………….................
[1 mark]

(ii) Explain why a very high voltage of 3000 V
is used in Diagram 4.1
.......................................................................
[1 mark]

(iii) State the energy changes 12
experience by the electrons
from anode to the screen. [1 m] (b) Explain how the bright spot is formed on the
screen of the C.R.O.
…………………………………………………… Terangkan bagaimana tompok cerah itu terbentuk
di atas skrin O.S.K.
(b) The voltage between the cathode
and anode is 3000 V. The charge of an ……………………………………………………………..
electron is 1.6 x 10-19 C. Calculate the kinetic
energy possesses by an electron as it ……………………………………………………………..
reaches the anode. [2 marks] [2 marks]

(c)(i) 1000 V power supply is (c) Diagram 4.2 shows the bright spot is
connected to the top and lower plates. The displaced to Q when a direct current, d.c.
top plate is connected to the positive supply, is connected to the Y-input of the
terminal and the lower plate is connected to C.R.O.
the negative terminal. Sketch the path of the Rajah 4.2 menunjukkan tompok cerah itu tersesar
cathode rays in Diagram 4.2. ke Q apabila bekalan kuasa arus terus, a.t
disambung ke input-Y O.S.K itu.

[1 mark] Diagram 4.2
(c)(ii) From the answer in (c)(i), state one
characteristic of cathode rays. The Y-gain of the C.R.O is set at 2 V/division.
Calculate the input voltage of the d.c. supply.
……………………………………….. Gandaan Y O.S.K tersebut disetkan pada 2
V/bahagian. Hitungkan voltan input bekalan a.t.
2. SPM 2010: Question 4
Diagram 4.1 shows a bright spot, P, formed on the [2 marks]
screen of a cathode-ray oscilloscope, C.R.O., when (d) Diagram 4.3 shows an alternating current, a.c.
it is switched on.
Rajah 4.1 menunjukkan satu tompok cerah, P, supply, is connected to the C.R.O. The Y-gain
terbentuk di atas skrin sebuah osiloskop sinar kator, of the C.R.O remains at 2 V/division.
O.S.K., apabila suis dihidupkan. Rajah 4.3 menunjukkan satu bekalan arus ulang
alik, a.u. disambung ke O.S.K. Gandaan Y O.S.K
kekal pada 2 V/bahagian.

Diagram 4.1 Diagram 4.3

(a) What is the meaning of cathode-ray? Draw the output signal on the screen in
Apakah maksud sinar katod? Diagram 4.3 when the peak voltage of the a.c.
supply is 6 V and the time base is switched
……………………………………………………………… off.
[1 mark] Lukis isyarat output pada skrin dalam Rajah 4.3
apabila voltan puncak bekalan a.u ialah 6 V dan
suis dasar masa ditutup.

[2 marks]

3. Question 3: SPM 2013 13
Diagram 3.1 shows a simple cathode rays tube.
Cathode emits electrons when switch P is closed. 4. Question 4: SPM 2016
Rajah 3.1 menunjukkan satu osiloskop sinar katod yang Diagram 4.1 shows a cross section of a Maltese
ringkas memancarkan electron apabila suis P ditutup. Cross tube which is used to study the
characteristics of cathode rays. The cathode ray is
produced when electrons emitted from a heated
cathode.
Rajah 4.1 menunjukkan keratan rentas tiub Palang
Maltese yang digunakan untuk mengkaji sifat sinar
katoci Sinar katod dihasilkan apabila elektron terpancar
dari katod yang dipanaskan.

(a) Name the process that enables the
emission of electrons at the cathode.
Namakan proses yang membolehkan
pemancaran electron daripada katod.

………………………………………………………………

[1 mark]

(b) State one reason why the extra high (a) Name the process of emitting electrons from the
heated cathode.
voltage is used. Namakan proses pemancaran elektron dari
katodyang dipanaskan.
Nyatakan satu sebab mengapa voltan lampau
………………………………………………………………
tinggi digunakan. [1 mark] ……

……………………………………………………………… [1 mark]
(c) When electrons flow in the cathode rays (b) Diagram 4.2 shows a shadow and a green light
tube, the current produced in 5 seconds is
0.01 A. Calculate the total charge of the region seen on the screen.
electrons. Rajah 4.2 menunjukkan satu bayang dan
Apabila electron mengalir dalam tiub sinar kawasan cahaya hijau dilihat di atas skrin.
katod, arus dihasilkan dalam 5 saat ialah 0.01
A. Hitung jumlah cas electron.
[2 marks]

(d) Diagram 3.2 shows an incomplete path of a Give a reason why
Beri satu sebab mengapa
cathode ray in an electric field. (i) the shadow is formed on the screen.

Rajah 3.2 menunjukkan satu lintasan yang bayang terbentuk di at as skrin.
tidak lengkap bagi sinar katod dalam medan
elektrik. ………………………………………………………………

(i) In Diagram 3.2, complete the path of the (ii) the green light region is formed on the
screen,
cathode ray. kawasan cahaya hijau terbentuk di atas skrin.

………………………………………………………………
[2 marks]

Dalam Rajah 3.2, lengkapkan lintasan sinar

katod. [1 mark]

(ii) Give one reason for the answer in 3(d)(i).
Beri satu sebab untuk jawapan dalam 3(d)(i).

………………………………………………………………
[1 mark]

14

(c) Electrical potential energy 4.8 x 10-16 J gained by
an
electron is converted to kinetic energy of the
electron in the Maltese Cross tube. Calculate the
velocity of the electron.
[The mass of an electron, m = 9.0 x 10-31 kg ]
Tenaga keupayaan elektrik 4.8 x 10-16 J yang
diterima oleh satu electron ditukarkan kepada
tenaga kinetik untuk elektron tersebut dalam tiub
Palang Maltese.
Hitung halaju elektron tersebut.
[Jisim bagi satu elektron, m = 9.0 x 10-31 kg ]
[2 marks]

(d) Diagram 4.3 shows two magnets with opposite
poles are placed at the sides of the tube causing
the shadow being deflected.
Rajah 4.3 menunjukkan dua batang magnet dengan
kutub berlawanan diletakkan di sisi tiub tersebut
menyebabkan bayang itu terpesong.

(i) Diagram 4.4 shows front view of the screen
seen by the observer.
Rajah 4.4 menunjukkan pandangan hadapan
skrin yang dilihat oleh pemerhati.

In Diagram 4.4, draw an arrow to show the
direction of the deflected shadow.
Pada Rajah 4.4, lukis anak panah untuk
menunjukkan arah pesongan bayang tersebut.

[1 mark]
(ii) State the physics rule used to determine

the direction of the shadow.
Nyatakan petua fizik yang digunakan untuk
menentukan arah bayang tersebut.
...........................................................................

[1 mark]