FORM 5

CHAPTER 4
ELECTROMAGNETISM
FORCE ON A CURRENT CARRYING CONDUCTOR IN
A MAGNETIC FIELD
ELECTROMAGNETIC INDUCTION
TRANSFORMER
NAME : _____________________________________
FORM : ______________________________________
SCHOOL : ___________________________________

PHYSICS IS FUN
 4.1 FORCE ON A CURRENT CARRYING CONDUCTOR IN A
MAGNETIC FIELD

TEMPORARY MAGNET
ELECTROMAGNET

CURRENT CARRYING
Straight wire CONDUCTOR

Coil
Direction of magnetic field is
form NORTH to SOUTH
Solenoid
A magnetic field pattern can be represented by a field lines that show the shape of the field.
Magnetic field lines which are close together represent a strong field
The field direction is defined as the direction indicated by a compass needle placed in the magnetic field.
Magnetic Field : Region in which magnetic material experience magnetic force

RIGHT HAND GRIP RULE

SOLENOID
MAGNETIC FIELD PATTERN

STRAIGHT WIRE

Head
at
w
em Current
Out
ro 1
Ar

pit
Tail
T
I
Current
In

COIL

n
v

iii i
l
x

r
e

n v

SOLENOID

na

te x
is
 FACTORS THAT AFFECT THE STRENGTH OF THE ELECTROMAGNET

Current flowing in the solenoid Number of turns in solenoid

Distance between the turns Use of soft iron core

FORCE ON A CURENT CARRYING CONDUCTOR IN A MAGNETIC FIELD

When a current carrying conductor that is placed in a magnetic field produced by a pair of Magnadur magnet
(permanent magnet )= Magnetic Force is produced.

BE At
EA
Force on a current carrying conductor in a magnetic field is produced by the interaction between two magnetic field :
( magnetic field from the electric currents in the conductor and the magnetic field from the permanent magnet )
The 2 magnetic fields combine to produce a resultant magnetic field that is known as a Catapult field.
CATAPULT FIELD : resultant magnetic field produced by the interaction between the magnetic field from a current
carrying conductor and the magnetic field from a permanent magnet.
The pattern of the catapult field will show the direction of the force acting on the conductor.

The direction of the force on a current carrying conductor can be determined by using Fleming’s left –hand rule.
FACTORS AFFECTING THE MAGNITUDE OF THE FORCE ACTING ON A CURRENT –CARRYING
CONDUCTOR IN A MAGNETIC FIELD.

Increase current in the Use stronger permanent magnet

conductor decreases distance between N
T no ofbatteries and S pole
use curve magnet ( produce
radial magnetic field )
willproduce
itconstant
force
 EFFECT OF A CURRENT CARRYING COIL IN A MAGNETIC FIELD

The current – carrying coil in a magnetic field will rotate about the axis of rotation.
This rotation is due to a pair of forces of equal magnitude but in opposite direction acting on the sides of the coil.

DIRECT CURRENT MOTOR

Small electrical appliances have small direct current motor.

Larger direct current motors are found in machines such as electric vehicles, lift and roller in factories.
Direct current motor changes electrical energy to kinetic energy by using the turning effect of a current carrying coil in a
magnetic field.
F
 WHEN
SPEED OF
IRON AI MINCREASES

He
 4.2 ELECTROMAGNETIC INDUCTION

When a piece of copper wire is moved across magnetic flux, an electromotive force ( emf) is induced in the wire.
Electromagnetic induction : the production of induced emf in a conductor when there is relative motion between the
conductor and the magnetic field or when the conductor is in changing magnetic field.

Relative motion between 2 objects is the A B

motion that results in the two objects Relative motion occurs between objects A and B if:
becoming closer to each other or further A is stationary and B moves towards or away from A.
away from each other B is stationary and A moves towards or away from B.
A and B move with different velocities.
No relative motion between object A and B if:
A and B are stationary
A and B move with the same speed in the same direction

i
 FACTORS AFFECTING THE MAGNITUDE OF THE INDUCED EMF

Relative motion of a Straight wire and magnet, Relative motion of a Solenoid and magnet,
induced emf increases when induced emf increases when
speed of relative motion increases speed of relative motion increases
the strength of the magnetic field the strength of the magnetic field
increases increases
the number of turns of the solenoid
increases

FARADAY’S LAW

The magnitude of induced emf is directly proportional to the rate of cutting of magnetic flux
The magnitude of the emf increases if more magnetic field lines are cut in a certain period of time.

DIRECTION OF INDUCED CURRENT IN A STRAIGHT WIRE AND SOLENOID

1
at
 LENZ’S LAW
The induced current always flows in a direction that opposes the change of magnetic flux that causes it.
Is used to determine the polarity at the end of the solenoid when current is induced.

to

DIRECT CURRENT GENERATOR AND ALTERNATING CURRENT GENERATOR

 o roo

or nl
Bad
 EXERCISE 4.2

16 Diagram 7.1 shows an a.c. generator in which a coil is being turned in a magnetic field.
Rajah 7.1 menunjukkan sebuah penjana a.u. di mana satu gegelung diputar dalam
medan magnet.
Rotation / Putaran

N
S
Slip ring
Gelang gelincir

Diagram / Rajah 7.1

(a) (i) What is the meaning of magnetic field?
Apakah maksud medan magnet?

..........................................................................................................................
[1 mark/markah]

(ii) Why does the bulb light up?

Mengapakah mentol itu menyala?

..........................................................................................................................
[1 mark/markah]

(b) Some modifications need to be done to the a.c. generator in Diagram 7.1 to
convert it into a d.c. motor.
Beberapa pengubahsuaian perlu dilakukan terhadap penjana a.u. dalam Rajah
7.1 untuk menjadikannya sebuah motor a.t.

(i) State the modification that has to be done to the slip rings.
Nyatakan pengubahsuaian yang perlu dilakukan terhadap gelang gelincir.

..........................................................................................................................
[1 mark/markah]

(ii) What component should replace the light bulb?

Apakah komponen yang harus menggantikan mentol?

..........................................................................................................................
[1 mark/markah]
(c) Diagram 7.2 shows the cross-sectional view of the coil and magnet of the d.c.
motor.
Rajah 7.2 menunjukkan pandangan keratan rentas bagi gegelung dan magnet
bagi motor a.t. itu.

Current out
Arus keluar
N S
Current in
Arus masuk

Diagram / Rajah 7.2

In Diagram 7.2, draw the resultant magnetic field that causes the coil to rotate.
Show the direction of the force, F, that acts on the coil.
Dalam Rajah 7.2, lukis medan magnet paduan yang menyebabkan gegelung itu
berputar.
Tunjukkan arah daya, F, yang bertindak ke atas gegelung itu.
[2 marks/markah]
(d) Further modifications need to be done to make the motor turn faster.
State the modifications and give a reason for your answers.
Pengubahsuaian selanjutnya perlu dilakukan untuk membuat motor itu berputar
dengan lebih laju.
Nyatakan pengubahsuaian itu dan beri sebab bagi jawapan anda.

(i) The coil / Gegelung :

…......................................................................................................................

Reason / Sebab :

..........................................................................................................................
[2 marks/markah]

(ii) The magnet / Magnet :

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

Reason / Sebab :

..........................................................................................................................
[2 marks/markah]
17 Diagram 7.1 show a coil PQ, made of copper wire is connected to a sensitive galvanometer to study
the effect of electromagnetic induction.
Rajah 7.1 menunjukkan suatu gegelung PQ, diperbuat daripada dawai kuprum disambungkan
kepada suatu galvanometer peka untuk mengkaji kesan aruhan elektromagnet.

Permanent mgnet
Magnet kekal Galvanometer
Galvanometer

Elastic spring
Spring elastik Coil
Gegelung

Diagram 7.1/ Rajah 7.1

a) Explain the meaning of
Terangkan maksud
(i) Electromagnetic induction.
aruhan elektromagnet.

…………………………………………………………………………………………………
[1 mark/ markah]
(ii) Faraday’s law. / hukum Faraday.

…………………………………………………………………………………………………
[1 mark/ markah]
b) A small permanent magnet which is connected to the end of an elastic spring oscillates in and
out of the end, P, of the coil as shown in Diagram 7.1 above.
Suatu magnet kekal kecil yang disambungkan pada hujung suatu spring elastik berayun masuk
keluar hujung Pgegelung itu seperti ditunjukkan dalam Rajah 7.1 di atas.

(i) Describe what happens to...

Perihalkan apa yang berlaku kepada...
1. the circuit containing coil PQ,
litar yang mengandungi gegelung PQ.

…………………………………………………………………………………..
[1 mark/ markah]
2. the galvanometer.
galvanometer itu.

…………………………………………………………………………………..
[1 mark/ markah]
 (ii) What is the magnetic pole formed at the end, P, when the permanent magnet is moving
away from P?
Apakah kutub magnet yang terbentuk pada hujung P apabila magnet kekal berayun
menjauhi P?

……………………………………………………………………………………
[1 mark/ markah]

(iii) State the name of the law you have used to determine your answer in (b)ii.
Nyatakan nama hukum yang anda gunakan untuk menentukan jawapan anda
dalam (b)ii.

……………………………………………………………………………………
[1 mark/ markah]
c) (i) It is found that the oscillation of the permanent magnet stops after a few seconds. What
happens to the kinetic energy of the permanent magnet when it stops oscillating?
Didapati ayunan magnet kekal berhenti selepas beberapa saat. Apakah yang berlaku
kepada tenaga kinetik magnet itu apabila ia berhenti mengayun?

……………………………………………………………………………………..
[1 mark/ markah]
(ii) State two modifications which should be made in the apparatus set up as shown in
Diagram to increase the induced current.
Nyatakan dua modifikasi yang harus dibuat pada susunan radas dalam Rajah di
atas supaya arus aruhan dapat ditingkatkan.

……………………………………………………………………………………..

……………………………………………………………………………………..
[2 mark/ markah]
d) Name one electrical appliance which operates on the principle of electromagnetic
induction.
Berikan nama satu alat elektrik yang berfungsi berasas prinsip aruhan elektromagnet.

………………………………………………………………………………………………
[1 mark/ markah]
FIZIK KERTAS 2 SPM

6 Diagram 6.1 shows a piece of bar magnet is moved into a solenoid.

The pointer of centered zero galvanometer is deflected caused by induced current.
Rajah 6.1 menunjukkan sebatang magnet bar digerakkan masuk ke dalam satu
solenoid. Penunjuk galvanometer berpusat sitar didapati terpesong disebabkan oleh
arus aruhan.

Solenoid
Diagram 6.1
Rajah 6.1

Diagram 6.2 shows two pieces of bar magnet are moved into the identical solenoid.
The pointer of centered zero galvanometer also deflected.
Rajah 6.2 menunjukkan dua batang magnet bar digerakkan masuk ke dalam solenoid
yang serupa. Penunjuk galvanometer berpusat sitar juga terpesong.

Solenoid
Diagram 6.2
Rajah 6.2

(a) What is the meaning of induced current?

Apakah yang dimaksudkan dengan arus aruhan?

[1 mark]

(b) Referring to the Diagram 6.1 and Diagram 6.2, compare

Merujuk kepada Rajah 6.1 dan Rajah 6.2, bandingkan

(i) the number of turns of the solenoid.

bilangan lilitan solenoid.

[1 mark]

MPP3 2019 10
FIZIK KERTAS 2 SPM

(ii) the strength of magnetic field.

kekuatan medan magnet.

[1 mark]

(iii) the magnitude of induced current.

magnitud arus aruhan.

[1 mark]

(c) (i) Based on your answer at (b), state the relationship between the strength of
magnetic field and the magnitude of induced current.
Berdasarkan jawapan anda di (b), nyatakan hubungan antara kekuatan
medan magnet dan magnitud arus aruhan.

[1 mark]

(ii) Name the Physics Law involved in (c)(i).

Namakan Hukum Fizik yang terlibat dalam (c)(i).

[1 mark]

(d) Diagram 6.3 shows a solenoid PQ is connected to a battery. A bar magnet is hung
beside the edge Q of the solenoid.
Rajah 6.3 menunjukkan sebuah solenoid PQ yang disambung ke sebuah bateri.
Satu magnet bar digantung bersebelahan dengan hujung Q solenoid itu.

Bar magnet
Magnet bar

fir-{
Diagram 6.3
Rajah 6.3

When the switch S is on, explain what will happens to the bar magnet.
Apabila suis S dihidupkan, terangkan apakah yang akan terjadi kepada magnet bar.

[2 marks]

MPP3 2019 11
22. Diagram 6.1 and Diagram 6.2 shows a magnet bar is moved away from a solenoid.
Rajah 6.1 dan Rajah 6.2 menunjukkan sebatang bar magnet digerakkan menjauhi suatu
solenoid.

Diagram 6.1 Diagram 6.2

Rajah 6.1 Rajah 6.2

The pointer of the galvanometer deflects in both diagrams.

Penunjuk galvanometer terpesong dalam kedua-dua rajah.

(a) What is the physics concept involved in the situation above?

Apakah konsep fizik yang terlibat dalam situasi di atas?

…………………………………………………………………………………………………
[1 mark/markah]

(b) What is the polarity at R?

Apakah kekutuban pada R?

…………………………………………………………………………………………………
[1 mark/markah]

(c) Based on Diagrams 6.1 and 6.2,

Berdasarkan Rajah 6.1 dan 6.2,

(i) compare the number of turns of the solenoid.

bandingkan bilangan lilitan pada solenoid.

……………………………………………………………………………………………
[1 mark/markah]
 (ii) compare the speed of motion of the bar magnet.
bandingkan laju gerakan magnet bar tersebut.

……………………………………………………………………………………………
[1 mark/markah]

(iii) compare the deflection of the pointer of galvanometer.

bandingkan pemesongan penunjuk galvanometer tersebut.

……………………………………………………………………………………………
[1 mark/markah]

(iv) relate the speed of motion of the bar magnet and the magnitude of induced
current produced.
hubungkaitkan laju gerakan magnet bar dan magnitude arus aruhan yang
terhasil.

……………………………………………………………………………………………

……………………………………………………………………………………………
[1 mark/markah]

(d) (i) What happens to the galvanometer reading if the bar magnet and the solenoid
are moved together to the left with speed of 20 m s-1?
Apakah yang berlaku pada bacaan galvanometer jika magnet bar dan solenoid
digerakkan bersama-sama ke kiri dengan laju 20 m s-1?

……………………………………………………………………………………………

……………………………………………………………………………………………
[1 mark/markah]
 4.3 TRANSFORMER
A transformer is an electrical device which increases or decreases an alternating voltage
based on the principle of electromagnetic induction

WORKING PRINCIPLE OF A SIMPLE TRANSFORMER

STRUCTURE OF A SIMPLE TRANSFORMER

Consists of two coils of wire wound round
separated on a laminated soft iron core
The coil connected to the input voltage is
called the primary coil.
The coil connected to the output voltage is
called the secondary coil.
The purpose of the common iron core is to
provide a magnetic field linkage in the
secondary coil.

OPERATING PRINCIPLE OF A SIMPLE TRANSFORMER

The frequency of the secondary voltage, Vs is the same as primary voltage, Vp.
The magnitude of the secondary voltage, Vs, depends on the ratio of the number of turns of the
primary and secondary coils.
According to Faraday’s Law :
Voltage is α number of turns in coil
 Why does the transformer not work with dc power supply?
A current is induced in the secondary coil only
ones when there is a changing magnetic flux due to a
changing primary current
(changes direction and magnitude )
A dc power supply gives a constant current in
the primary circuit ( does not create a changing
magnetic flux in the secondary coil)
Electromagnetic induction does not take place

STEP UP TRANSFORMER STEP DOWN TRANSFORMER

tattoo
__ dB

of
Microwave oven Notebook computer charger
Defibrillators Photocopy machine
X-ray machine Welding machine

RELATIONSHIP BETWEEN OUTPUT POWER AND INPUT POWER OF AND IDEAL TRANSFORMER

A transformer transfer electrical energy power from the primary circuit to the secondary
circuit.
The primary circuit of a transformer receives power at a certain voltage from the ac power
supply.
The transformer delivers this power at another voltage to an electrical device connected to
the secondary circuit.
In a real, transformer experiences a loss of energy especially in the form of heat
The output power is less than the input power. Therefore the efficiency if the transformer is
less than 100%.

Efficiency, η =

An ideal transformer is a transformer that does not experience any loss of energy, that is the
efficiency, η is 100%
 WAYS TO INCREASE THE EFFICIENCY OF A TRANSFORMER

Working principle of transformer involves processes such as the flows of current on the
copper coils, the changes of magnetic field and the electromagnetic induction.
These processes cause loss of energy and the transformer is unable to operate at an
optimum level.
Most of the energy is lost in the form of heat energy.
The power loss is due to :

WAY TO REDUCE ENERGY LOSS IN A TRANSFORMER

EDDY CURRENT : Use in an induction cooker
High frequency alternating current in the
coil producing a magnetic field that
changes with a high frequency.
This magnetic field induces eddy currents
at the base of the pan.
The eddy currents heat up the base of the
pan.

ELECTRICAL ENERGY TRANSMISSION AND DISTRIBUTION SYSTEM ( National Grid Network )

Transformer plays an important role in the transmission and distribution of electricity from
power station to consumers.

STEP – UP TRANSFORMER : At stage of transmission of electrical energy, step – up

transformer are used to increase the voltage in the power cable so that the current in the
power cable becomes small. This reduces the loss of electrical energy from the power cable.

STEP- DOWN TRANSFORMER : During distribution of electrical energy, step-down

transformer are used to decrease the voltage in the power cable in stage to a suitable value
for industrial and residential consumers.

POWER LOSS POWER TRANSMISSION

P loss = I2R PTrans = VI

I = current in the cable I = current in the cable
R = resistance of the cable V = voltage of the cable
 EXERCISE

28 Diagram 1 shows an application of transformer in daily life.

Rajah 1 menunjukkan aplikasi transfomer dalam kehidupan seharian.
Soft iron core
Teras besi lembut

Input 240 Va.c

Input 240 Va.u

Output 12 Va.c Diagram 1

Output 12 Va.u Rajah 1

(a) Complete the following sentence by ticking ( √ ) in the box.

Lengkapkan ayat berikut dengan menandakan (√) pada kotak yang betul.
The type of transformer used in Diagram 1 is
Jenis transformer yang digunakan dalam Rajah 1 ialah
Step up transformer Step down transformer [1 mark]
Transformer injak naik Transformer injak turun [1 markah]

(b) State the function of the transformer in 1(a)

Nyatakan kegunaan transformer dalam 1(a).

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

(c) Draw the symbol for your answer in 1(a).

Lukiskan simbol untuk jawapan anda di 1(a).

[1 mark]
[1 markah]

(d) Why is soft iron used as core in the transformer?

Mengapakah besi lembut digunakan sebagai teras dalam transformer?

……………………………………………………………………………..
[1 mark]
[1 markah]
29 Diagram 3 shows a simple transformer.
Rajah 3 menunjukkan sebuah transformer ringkas.

Diagram 3 / Rajah 3

(a) (i) Name the type of the transfomer.

Namakan jenis transfomer itu.

...........................................................................................................................................
[ 1 mark / markah ]

(ii) State one suitable material to be used as the transfomer core and give one reason for
your choice.
Nyatakan satu bahan yang sesuai digunakan sebagai teras transformer itu dan beri
satu sebab bagi pilihan anda.

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

...........................................................................................................................................
[ 2 marks / markah ]

(b) The number of turns on the secondary coil is 2500. Calculate the number of turns on the
primary coil.
Bilangan lilitan pada gegelung sekunder itu ialah 2500. Hitung bilangan lilitan pada
gegelung primer itu.

[ 2 marks / markah ]
30 Diagram 4.1 shows an electrical energy transmission system used in Malaysia.
Rajah 4.1 menunjukkan suatu sistem penghantaran tenaga elektrik yang digunakan
di Malaysia.

Diagram 4.1
Rajah 4.1

(a) What is the name of the system?

Apakah nama sistem itu?

……………………………………………………………………………………... 4(a)
[1 mark]
[1 markah] 1

(b) Electrical energy produced by a power station is transmitted at high voltage

through the cables on pylon.
Tenaga elektrik yang dihasilkan oleh stesen janakuasa dihantar dengan voltan
yang tinggi melalui kabel di atas pilon.

(i) What is the type of transformer P?

Apakah jenis transformer P?

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

(ii) Explain why is the electricity at high voltage is used during transmission
through cables.
Terangkan mengapa elektrik bervoltan tinggi digunakan semasa
penghantaran melalui kabel.

…………………………………………………………………………………

…………………………………………………………………………………

…………………………………………………………………………………
[2 marks]
[2 markah]
 (c) Diagram 4.2 shows a simple transformer with output power 3.6 W.
Rajah 4.2 menunjukkan sebuah transformer ringkas dengan kuasa output 3.6 W.

Diagram 4.2
Rajah 4.2

(i) Calculate the input current.

Hitungkan arus input.

[2 marks]
[2 markah]

(ii) State one assumption that you have made in 4(c)(i).

Nyatakan satu andaian yang anda buat dalam 4(c)(i).

……………………………………………………………………………….....
[1 mark]
[1 markah]
31 Diagram 4 shows a transformer connected to a 240 V a.c. power supply. The output are connected to 3
bulbs which are arranged in parallel.
Rajah 4 menunjukkan sebuah transformer yang disambung kepada bekalan kuasa 240 V a.u. Output
disambung kepada 3 mentol yang disambung secara selari.

Diagram 4
Rajah 4
(a) Name the type of transformer shows in Diagram 4.
Nyatakan jenis transformer yang ditunjukkan dalam Rajah 4.

….…………………………………………………………………………………………………..
[1 mark/ 1 markah]

(b) Calculate the output voltage of the transformers.

Hitungkan voltan output bagi transformer tersebut.

[1 mark/ 1 markah]

(c) When turned on, a current of magnitude of 0.25 A flows in the primary coil and all the bulbs
lighted up with normal brightness.
Bila dihidupkan, arus bermagnitud 0.25 A mengalir dalam gegelung primer dan semua mentol
nyala dengan kecerahan normal.

(i) What is the input power of the transformers?

Berapakah kuasa input transformer?

[2 mark/ 2 markah]
(ii) Calculate the efficiency of transformer in Diagram 4.
Hitungkan kecekapan transformer dalam Rajah 4

[2 marks/ 2 markah]

(iii) Suggest one way to increase the efficiency of a transformer.

Cadangkan satu cara untuk meningkatkan kecekapan suatu transformer.

….………………………………………………………………………………………….
[1 mark/ 1 mark]
35. Diagram 4 shows an electric mosquito zapper connected to a 240 V a.c. power supply.
Mosquitoes are attracted to the fluorescent lamp in the electric mosquito zapper and
instantly killed as they fly towards the lamp and made contact with the metal grids.
Rajah 4 menunjukkan sebuah perangkap nyamuk elektrik yang disambung kepada
bekalan kuasa a.u. 240 V.
Nyamuk akan tertarik dengan lampu pendarfluor di dalam perangkap nyamuk dan
akan mati serta-merta semasa terkena grid logam apabila cuba mendekati lampu.

Diagram 4
Rajah 4

(a) A transformer is used in the electric mosquito zapper. The voltage across the
primary coil is 240 V and the voltage across the secondary coil is 2880 V.
Transformer digunakan dalam perangkap nyamuk elektrik. Voltan pada
gegelung primer adalah 240 V dan voltan pada gegelung sekunder adalah
2 880 V.
 (i) Name the type of transformer used in the electric mosquito zapper.
Nyatakan jenis transformer yang digunakan dalam perangkap nyamuk
elektrik tersebut.

..................................................................................................................
[1 mark]
[1 markah]

(ii) How does the alternating current flows through the primary coil
produces a changing e.m.f. across the secondary coil?
Bagaimanakah arus ulang alik yang mengalir pada gegelung primer
boleh menghasilkan d.g.e. yang berubah-ubah pada gegelung
sekunder?

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

..................................................................................................................
[2 marks]
[2 markah]

(b) Why iron core is used in the transformer in Diagram 4?

Mengapakah teras besi digunakan dalam transformer dalam Rajah 4?

...............................................................................................................................
[1 mark]
[1 markah]

(c) The efficiency of the transformer is 85%.

Kecekapan transformer tersebut ialah 85%.

(i) Calculate the input current when the output power is 20 W.

Hitung arus input apabila kuasa output ialah 20 W.
.

[2 marks]
[2 markah]
SULIT 33 4531/2

12 Diagram 12.1 shows two transformers P and Q.

Rajah 12.1 menunjukkan dua tranformer P dan Q.
Transformer P Transformer Q

vp = 240 v VP=110V
Np =2000 Np = 500
N5 = 500 N5 = 1000

Diagram 12.1
Rajah 12.1

(a) (i) Which transformer is the step-up transformer?

Yang manakah tarnsformer injak naik?
[1 mark]
[1 markah]

(ii) Explain the working principle of a transformer.

Terangkan prinsip kerja sebuah transformer.
[4 marks]
[4 markah]

(b) Rajah 12.2 shows a circuit consisting of a transformer, an ammeter and two light
bulbs. The ammeter reading is 0.5 A and both bulbs light up with normal
brightness.
Rajah 12.2 menunjukkan satu litar yang terdiri daripada sebuah transformer,
satu ammeter dan dua mental. Bacaan ammeter ialah 0.5 A dan kedua-dua
mental itu menyala dengan kecerahan normal.

240 Va.u.

Bulb Bulb
Mento! Mento!
12V, 24 W 12 v, 24 w

Diagram 12.2
Rajah 12.2

[Lihat halaman sebelah

4531/2 © 2019 Hak Cipta MPSM Negeri Sembilan SULIT
SULIT 34 4531/2

(i) What is the output voltage of the transformer?

Berapakah voltan output transformer itu?

(ii) Calculate the efficiency of the transformer.

Hitungkan kecekapan transformer itu.
[5 marks]
[5 markah]

(c) The transmission of electricity throughout the National Grid Network uses high
voltage cables. You are assigned to study the characteristics of cables which could
be suitable as a transmission cable.
Table 12 shows the characteristics of four transmission cables.
Penghantaran tenaga elektrik melalui Rangkaian Grid Nasional menggunakan
kabel yang mempunyai voltan yang tinggi. Anda diminta unuk mengkaji ciri-ciri
kabel yang mungkin sesuai digunakan sebagai kabel penghantaran.
Jadual12 menunjukkan ciri-ciri bagi empatjenis kabel penghantaran.

Cable Resistivity/ Density I Cost Rate of thermal

Kabel Kerintangan Ketumpatan Kos expansiOn
(Q m-1) (kg m-3) Kadar pengembangan
term a
Low High
p 3.o x 10-7 5 X 105
Rendah Tinggi
Medium Low
Q 1.8 x 10-s 2 X 103
Sederhana Rendah
High Medium
R 7.5 x 10-7 8 X 102
Tinggi Sederhana
Medium
s 7.0x10-8 4 X 103
Sederhana
High
Tinggi

Table 12
Jadual12

Explain the suitability of the characteristics of the cables to be used as transmission

cable. Determine the most suitable transmission cable to be used and give reasons
for your choice.
Jelaskan ciri-ciri kabel yang sesuai dijadikan kabel penghantaran. Tentukan kabel
yang paling sesuai digunakan sebagai kabel penghantaran dan beri sebab atas
pilihan anda.
[10 marks]
[10 markah]

END OF QUESTION PAPER

KERTAS SOALAN TAMAT

4531/2 © 2019 Hak Cipta MPSM Negeri Sembilan SULIT

 OBJECTIVE QUESTIONS Bab 4: Elektromagnet |1
4.3 Transformer

1. Transformer are used to increase or decrease the voltages of alternating current.

Transformer losses are produced by the electrical current flowing in the coil and the
magnetic field alternating in the core.
Transformer ialah alat yang digunakan untuk menaikkan atau menurunkan voltan arus
ulang alik. Kehilangan kuasa dalam transformer dihasilkan oleh pengaliran arus elektrik di
dalam gegelung dan medan magnet yang mengaruh di dalam teras.

Which transformer A, B, C and D has the highest efficiency?

Antara transformer A, B, C dan D, yang manakah mempunyai kecekapan paling tinggi?
Type of transformer core Wire materials
Jenis teras transformer Bahan dawai
A. Solid soft iron core Copper
Teras besi lembut Kuprum
B. Laminated soft iron core Copper
Teras besi lembut berlamina Kuprum
C. Solid copper core Constantan
Teras kuprum pepejal Konstantan
D. Solid copper core Constantan
Teras kuprum pepejal Konstantan

2. Diagram 2 shows an electrical cable grid system that transmits electrical energy from the
power station for domestic use.
Rajah 2 menunjukkan sistem grid kabel elektrik yang memindahkan tenaga elektrik
daripada stesen kuasa kepada pengguna.

Diagram / Rajah 2
Why is the electrical energy transmitted at a high potential difference?
Mengapakah tenaga elektrik dipindahkan pada beza keupayaan tinggi?
A. To increase the current in the cables
Untuk meningkatkan arus yang mengalir dalam kabel
B. To reduce the resistance of the cable
Untuk mengurangkan rintangan kabel
C. To increase the speed of transmission of energy
Untuk meningkatkan kadar penghantaran tenaga
D. To reduce the power dissipated in the cables
Untuk mengurangkan kuasa yang hilang dalam kabel
 Bab 4: Elektromagnet |2
4.3 Transformer

3. Diagram 3 shows two coils are wounded on an iron ring. When the switch is closed, what
will happen to the bulb connected to the secondary coil?
Rajah 3 menunjukkan dua gegelung dililitkan pada satu gelang besi. Apabila suis dipasang,
apakah yang berlaku kepada mentol yang disambung kepada gegelung sekunder?
Primary coil Secondary coil
Gegelung primer Gegelung sekunder

Battery Bulb
Bateri Mentol

Diagram / Rajah 3

A. Lighted up with increasing brightness.

Menyala dengan kecerahan yang semakin meningkat
B. Flashed at a constant frequency
Berkelip pada frekuensi yang tetap
C. Flashed only ones
Berkelip hanya sekali
D. Not lighted up
Tidak menyala

4. Diagram 4 shows the number of turns between each pair of output terminals of a
transformer. Between which pair of output terminals, the output voltage is 12 V?
Gambarajah 4 menunjukkan bilangan lilitan pada pasangan terminal output suatu
transformer. Pasangan terminal output yang manakah, voltan output adalah 12 V?
P
10 turns
10 lilitan
Q
20 turns
20 lilitan
20 turns R
6V 20 lilitan

40 turns
40 lilitan
S
Diagram / Rajah 4

A. R and S C. Q and R
B. P and Q D. P and R

5. The purpose of using laminated iron core in a transformer is to

Tujuan penggunaan teras besi berlamina dalam transformer ialah untuk

A. reduce resistance
mengurangkan rintangan
B. reduce eddy current
mengurangkan arus pusar
C. prevent flux leakage
menghalang kebocoran fluks
D. magnetized and demagnetized iron core easily.
senang memagnet dan menyahmagnetkan teras besi
 Bab 4: Elektromagnet |3
4.3 Transformer

6. Diagram 6 shows a transformer used to change an input voltage of 240 V to 12 V.

Rajah 6 menunjukkan sebuah transformer digunakan untuk menukarkan voltan input 240 V
kepada 12 V.

240 V a.c
V 12 V
240 V a.u

1200 turns
1200 lilitan
Diagram / Rajah 6
If the primary coil has 1 200 turns, how many turns must the secondary coil have?
Jika gegelung primer mempunyai 1 200 lilitan, berapakah bilangan lilitan yang
diperlukan untuk gegelung sekunder?
A. 24 000 C. 600
B. 12 000 D. 60

7. Diagram 7 shows a transformer.

Rajah 7 menunjukkan sebuah transformer.

a.c
a.u

Secondary coil
Primary coil
Gegelung sekunder
Gegelung primer
Diagram / Rajah 7
Which statement about the transformer is correct?
Pernyataan manakah yang betul mengenai transformer itu?
A. Its output power is always greater than its input power
Kuasa outputnya selalu melebihi kuasa inputnya
B. Its efficiency is increased by using laminated steel core
Kecekapannya ditingkatkan dengan menggunakan teras keluli berlamina
C. It is used to alter the potential difference of direct current
Ia digunakan untuk mengubah beza keupayaan arus terus
D. Its operating principle is based on electromagnetic induction
Prinsip operasinya berdasarkan aruhan elektromagnet

8. Diagram 8 shows a part of National Grid Network in the transmission of electricity.

Rajah 8 menunjukkan sebahagian daripada Rangkaian Grid Nasional dalam penghantaran
elektrik.

Diagram / Rajah 8
The energy dissipated during the transmission can be reduced by
Tenaga yang hilang semasa penghantaran boleh dikurangkan dengan
 Bab 4: Elektromagnet |4
4.3 Transformer

A. using high resistivity cable

menggunakan kabel yang mempunyai kerintangan tinggi
B. using a low-density cable
menggunakan kabel berketumpatan rendah
C. using high voltage
menggunakan voltan tinggi
D. using high current
menggunakan arus yang tinggi

9. Transformers are used in transmission of electricity to reduce energy loss by

Transformer digunakan dalam penghantaran kuasa elektrik untuk mengurangkan
kehilangan tenaga melalui

A. providing better insulator

menyediakan penebat yang lebih baik
B. reducing the resistance of the cable
mengurangkan rintangan kabel
C. increasing the thickness of the cable
menambahkan ketebalan kabel
D. reducing current by increasing voltage
mengurangkan arus dengan meningkatkan beza keupayaan

10. Which of the option is correct about the electricity transmission from the power station to the
consumers?
Antara pilihan berikut yang manakah betul tentang sistem penghantaran tenaga elektrik dari
stesen kuasa ke rumah pengguna?

Type of current Magnitude of voltage supply

Jenis arus Magnitud voltan yang dihantar
A. Direct current High voltage
Arus terus Voltan tinggi
B. Alternating current High voltage
Arus ulang alik Voltan tinggi
C. Direct current Low voltage
Arus terus Voltan rendah
D. Alternating current Low voltage
Arus ulang alik Voltan rendah

11. Diagram 11 shows a transformer that is used to light up a bulb.

Rajah 11 menunjukkan sebuah transformer yang digunakan untuk menghidupkan sebiji
mentol.

240 V
a.c

200 turns 50 turns

200 lilitan 50 lilitan
Diagram / Rajah 11
 Bab 4: Elektromagnet |5
4.3 Transformer

Which of the following statements is true about the transformer?

Antara pernyataan-pernyataan yang berikut, yang manakah benar tentang transformer itu?
Type of transformer Voltage across the bulb
Jenis transformer Voltan merentasi mentol
A. Step-up
480 V
Injak naik
B. Step-up
960 V
Injak naik
C. Step-down
50 V
Injak turun
D. Step-down
60 V
Injak turun

12. Which of the following transformer will lights up the 12 V bulb at its normal brightness?
Antara transformer berikut yang manakah akan menyalakan mentol 12 V dengan kecerahan
normal?

A.

240 V
a.c

1600 turns 12 turns

1600 lilitan 12 lilitan
B.

240 V
a.c

1600 turns 80 turns

1600 lilitan 80 lilitan
C.

240 V
a.c

1600 turns 100 turns

1600 lilitan 100 lilitan
D.

240 V
a.c

1600 turns 240 turns

1600 lilitan 240 lilitan
 Bab 4: Elektromagnet |6
4.3 Transformer

13. Diagram 13 shows an ideal transformer used to light up a bulb at normal brightness.
Rajah 13 menunjukkan sebuah transformer unggul digunakan untuk menyalakan satu lampu
pada kecerahan normal.
IP

240 V
a.c 48 W

Diagram / Rajah 13
What is the current IP?
Berapakah arus IP?
A. 0.2 A C. 5.0 A
B. 1.2 A D. 8.0 A

14 Diagram 14 shows the structure of an ideal transformer.

Rajah 14 menunjukkan satu struktur transformer yang unggul.

240 V
a.c

8000 turns 200 turns

8000 lilitan 200 lilitan
Diagram / Rajah 14
What is the potential difference across the bulb?
Berapakah beza keupayaan yang merentasi mentol itu?
A. 6 V C. 96 V
B. 60 V D. 200 V

15. Diagram 15 shows a transformer circuit.

Rajah 15 menunjukkan litar sebuah transformer.
Primary coil Secondary coil
Gegelung primer Gegelung sekunder

A
V

Diagram / Rajah 15
What happens if the number of turns of the secondary coil is increased?
Apakah yang berlaku jika bilangan gegelung sekunder ditambahkan?
A. The electric current in the primary coil decreases
Arus elektrik dalam gegelung primer berkurang
B. The electric current in the secondary coil increases
Arus elektrik di dalam gegelung sekunder bertambah
C. The potential difference across the secondary coil increases
Beza keupayaan merentasi gegelung sekunder bertambah
D. The potential difference across the secondary coil decreases
Beza keupayaan merentasi gegelung sekunder berkurang
 Bab 4: Elektromagnet |7
4.3 Transformer

16. Diagram 16 shows a multi-tap transformer.

Rajah 16 menunjukkan sebuah transformer multi-salur.

Diagram / Rajah 16
At which terminals should a 12 V bulb be connected such that it lights up with normal
brightness?
Pada terminal-terminal manakah sebuah mentol 12 V patut disambung supaya mentol
itu menyala dengan kecerahan normal?
A. P and Q C. P and S
B. P and R D. P and T

17. Diagram 17 shows an electric circuit which consists of an alternating current supply, a.c., a
transformer and two identical bulbs rated ‘12V 6W’.
Rajah 17 menunjukkan litar elektrik dengan bekalan arus ulang alik, a.u., sebuah
transformer dan dua mentol yang serupa berkadar ‘12V 6W’.

240 V a.c 12 V, 6 W
240 V a.u 12 V, 6 W

1000 turns 100 turns

1000 lilitan 100 lilitan
Diagram / Rajah 17
What happens to the bulbs if another identical bulb is connected in series to the secondary
circuit?
Apakah yang berlaku pada mentol jika sebuah lagi mentol serupa disambungkan secara
bersiri pada litar sekunder?
A. Become dimmer / Menjadi malap C. Blow up / Terbakar
B. Become brighter D. Light up with normal brightness
Menyala lebih cerah Menyala dengan kecerahan normal

18. Diagram 18 shows a simple transformer with bulb lights up at normal brightness.
Rajah 18 menunjukkan sebuah transformer ringkas dengan mentol menyala dengan
kecerahan biasa.

3V a.c
3 V a.u

Diagram / Rajah 18
What will happen if the alternating current, a.c input is replaced by a 3 V battery?
Apakah yang berlaku jika arus ulang alik digantikan dengan bateri 3V?
A. The bulb blows C. The brightness of the bulb increases
Mentol terbakar Kecerahan mentol bertambah
B. The brightness of the bulb decreases D. The bulb does not light up
Kecerahan mentol berkurang Mentol tidak menyala
 CHAPTER 10 ( ELECTROMAGNETISM)
29 4531/2

Bahagianc
SELANGOR Section C

[20 markah]
[20 marks]

Jawab semua soalan dalam bahagian ini.

Answer all question in this section.
11
Rajah l1.l dan Rajah l1.2 menunjukkan sebatangmagnet bar ditolak ke dalam solenoid dengan
laju yang sama.

Diagram l1.l and Diagram 11.2 showa bar magnet is beingpushed into a solenoid with the same
speed.

S/S
S/SUN

Galvanometer Galvanometer
Galvanometer Galvanometer
Rajah 11.I Rajah 11.2
Diagram l1.1 Diagram 11.2

(a) Apakah yang dimaksudkan dengan aruhan clektromagnet?

What is meant by electromagnetic induction?
[1 markah]
[1 mark]

(6) Berdasarkan Rajah 11.1 dan Rajah 11.2,

Based on Diagram 11.1 and Diagram 11.2,

(i) bandingkan bilangan lilitan solenoid, saiz pesongan penunjuk galvanometer dan
kadar pemotongan fluks magnet.
compare the number of turns of thesolenoid,thesize ofdeflection of thegalvanometer
pointer and the rate of cutting ofmagneticflux.

nyatakan hubungan bilangan lilitan solenoid dengan kadar pemotongan fluks magnet
(i) untuk membuat deduksi tentang hubungan antara kadar pemotongan fluks magnet
dan magnitud arus aruhan yang dihasilkan.
state the relationship between the number of turns of the solenoid with the rate of
cutting of magnetic fhux to make a deduction regarding the relationship between the
rate of cuting ofmagneticfux andmagnitude ofinducedcurrentproduced.
[5 markah]
[S marks]

4531/2 | Lihat halaman sebelah

 30 4531/2

(c) Rajah 11.3 menunjukkan satu transformer unggul.

Diagram 11.3 shows an ideal transformer.

Gegelungprimer Gegelung sekunder

Primary coil Secondary coil

Galvanometer
Galvanometer

Teras
Core

Rajah 11.3
Diagram 11.3

(i) Namakan jenis transformer ini.

Name this type of transformer.
[1 markah]
[1 mark]

(ii) Terangkan bagaimana arus diaruh di dalam gegelung sekunder.

Explain how current is induced in the secondary coil.
[3 markah]
[3 marks]

got

4531/2
 31 4531/2

() Rajah 11.4 menunjukkan struktur dinamo arus terus ringkas untuk menyalakan sebiji
mentol.

Diagram 114 shows a structure of simple direct current dynamo to light up a bulb.

Mentol Teras besi

Bulb Iron core

UNL
S/S
Roda
Wheel

Dawai gegelung Magnet

Wire coil Magnet
Rajah 11.4
Diagram 114

I Cadangkan pengubahsuaian yang boleh dilakukan pada dinamo dalam Rajah 11.4 supaya
mentol menyala lebih terang.
Nyatakan dan beri penerangan tentang pengubahsuaian itu berdasarkan ciri-ciri magnet,
ciri-ciri teras besi, ciri-ciri dawai gegelung, kuasa mentol dan cara-cara untuk menghasilkan
cahaya yang lebih terang.
Suggest modifications that can be made to the dynamo in Diagram 11.4, so that the bulb
lights up brighter.
State and explain the modifications based on the characteristics of the magnet,
characteristics of the iron core, characteristicsof the wire coil, power of the bulb and ways
to produce brighter light.
[10 markah]
[10 marks]

KERTAS PEPERIKSAAN TAMAT

END OF QUESTION PAPER

4531/2
MRSM
_0 Ae
SULIT 34 4531/2

10 Rajah 10.1 menunjukkan satu rod Kuprum disambungkan kepada galvanometer

berpusat sifar. Rod Kuprum digerakkan ke atas di antara dua magnet Magnadur
dengan kutub bertentangan.
Diagram 10.1 shows a Copper rod connected to a centre-zero galvanometer. The
Copper rod is moved upwards between the two Magnadur magnets that are of
opposite poles.

Arah gerakan rod Kuprum

Direction of Copper rod

Rod Kuprum
Copper rod

Rajah 10.1
Diagram 10.1

(a) (i) Namakan konsep fizik yang terlibat dalam Rajah 10.1. [1 markah]
Name the physics concept involved in Diagram 10.1. [1 mark]

(ii) Nyatakan satu faktor yang mempengaruhi pesongan jarum penunjuk

galvanometer. [1 markah]
State one factor which affect the deflection of galvanometer pointer.
[1 mark]

4531/2 © 2022 Hak Cipta Bahagian Pendidikan Menengah MARA SULIT

SULIT 35 4531/2

(b) Rajah 10.2 menunjukkan lampu suluh aruhan LED. Mentol LED menyala
bila lampu suluh digoncang secara mendatar.

Diagram 10.2 shows an induction LED torch light. The LED bulb lights up
when the torch light is shaken horizontally.

Gegelung
Mentol LED Coil
LED bulb

Magnet
Magnet

Papan litar
Circuit board

Rajah 10.2
Diagram 10.2

Terangkan bagaimana mentol LED menyala dengan lebih lama. [3 markah]

Explain how the LED bulb lights up for a longer time. [3 marks]

[Lihat halaman sebelah

4531/2 © 2022 Hak Cipta Bahagian Pendidikan Menengah MARA SULIT
SULIT 36 4531/2

(c) Rajah 10.3 menunjukkan litar suatu transformer yang digunakan untuk
mengecas sebuah kipas mudah alih.

Diagram 10.3 shows a circuit of transformer used to charge a portable fan.

240 V
Litar primer Litar sekunder 5 V, 5 W
Primary circuit Secondary circuit

Rajah 10.3
Diagram 10.3

(i) Berapakah nisbah bilangan lilitan primer, Np kepada bilangan lilitan

sekunder, Ns? [2 markah]
What is the ratio of number of turns of primary coil, Np to number of
turns of secondary coil, Ns? [2 marks]

(ii) Hitung arus sekunder. [2 markah]

Calculate the secondary current. [2 marks]

(iii) Jika transformer ini adalah unggul, berapakah nilai kuasa input?
[1 markah]
If the transformer is an ideal transformer, what is the value of the
input power? [1 mark]

(d) Rajah 10.4 menunjukkan dapur aruhan yang mengambil masa yang lama
untuk memanaskan makanan.

Diagram 10.4 shows an induction cooker takes a long time to heat up food.

Kuali
Pan
Permukaan atas dapur
Stove top
Gegelung
Coil

Ke bekalan kuasa
To power supply
Rajah 10.3
Diagram 10.3

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SULIT 37 4531/2

Jadual 2 menunjukkan empat jenis dapur aruhan K, L, M dan N.

Table 2 shows the characteristics of four induction cooker K, L, M and N.

Permukaan atas dapur: Seramik

Stove top: Ceramic

K Gegelung Nikrom
Nichrome coil
Kadar pengoksidaan
gegelung: Rendah Bekalan kuasa
Coil oxidation rate: Low Power supply

Permukaan atas dapur: Keluli

Stove top: Steel

L Gegelung Kuprum
Copper coil
Kadar pengoksidaan
gegelung: Tinggi Bekalan kuasa
Coil oxidation rate: High Power supply

Permukaan atas dapur: Seramik

Stove top: Ceramic

M Gegelung Kuprum
Copper coil
Kadar pengoksidaan
gegelung: Rendah Bekalan kuasa
Coil oxidation rate: Low Power supply

Permukaan atas dapur: Keluli

Stove top: Steel

N Gegelung Nikrom
Nichrome coil
Kadar pengoksidaan
gegelung: Tinggi Bekalan kuasa
Coil oxidation rate: High Power supply

Jadual 2
Table 2
[Lihat halaman sebelah
4531/2 © 2022 Hak Cipta Bahagian Pendidikan Menengah MARA SULIT
SULIT 38 4531/2

Anda dikehendaki menentukan dapur aruhan yang paling sesuai untuk

memanaskan makanan dengan cepat daripada aspek yang berikut:

You are required to determine the most suitable induction cooker to heat up
the food faster from the following aspects:

Bahan permukaan atas dapur

Material of stove top

Bahan gegelung
Material of coil

Kadar pengoksidaan gegelung

Coil oxidation rate

Bekalan kuasa
Power supply

Terangkan kesesuaian aspek-aspek itu dan tentukan dapur aruhan yang paling
sesuai. Beri sebab untuk pilihan anda.
Explain the suitability of the aspects and determine the most suitable
induction cooker. Give reasons for your choice.

[10 markah]
[10 marks]

4531/2 © 2022 Hak Cipta Bahagian Pendidikan Menengah MARA SULIT

 SULIT 4531/2
TERENGGANU
6. Rajah 6.1 dan Rajah 6.2 menunjukkan satu magnet bar dijatuhkan ke dalam dua
gegelung yang berbeza dari ketinggian yang sama.
Diagram 6.1 and Diagram 6.2 show a bar magnet is dropped into two different coils from
the same height.

Rajah 6.1
Diagram 6.1

Rajah 6.2
Diagram 6.2

(a) Namakan kuantiti fizik yang diukur oleh galvanometer.

Name the physical quantity measured by galvanometer.

... .
[1 markah]
[1 mark]

MPP3 13 AKRAM JPNT

SULIT 4531/2

(b) Berdasarkan Rajah 6.1 dan Rajah 6.2, bandingkan

Based on Diagram 6.1 and 6.2, compare

(i) kekuatan medan magnet bagi magnet bar.

the strength of magnetic field of the bar magnet.

[1 markah]
[1 mark]
(ii) bilangan lilitan gegelung
the number of turns of the coils

[1 markah]
[1 mark]

(iii) Saiz pesongan penunjuk galvanometer

Size of deflection of the galvanometer pointer

[1 markah]
[1 mark]

(c) Berdasarkan jawapan anda di 6(b), nyatakan

Based on your answer in 6(b), state
(i) hubungan antara bilangan lilitan gegelung dengan saiz pesongan penunjuk
galvanometer.
State the relationship between the number of turns of the coil with the size of
deflection of the galvanometer.

[1 markah]
[1 mark]
(ii) hubungan antara bilangan lilitan gegelung dengan kadar perubahan fluks
magnet.
State the relationship between the number of turns of the coil with rate of
change of magnetic flux.

[1 markah]
[1 mark]

MPP3 14 AKRAM JPNT

SULIT 4531/2

(d) Rajah 6.3 menunjukkan sebuah transformer ringkas yang disambung kepada motor
elektrik 12V, 24 W arus ulangalik.
Diagram 6.3 shows a simple transformer which is connected to an alternating
current 12V, 24 W electric motor.

Rajah 6.3
Diagram 6.3

(i) Hitung arus yang mengalir dalam gegelung sekunder itu.

Calculate the current flow in the secondary coil.

[2 markah]
[2 marks]
(ii) Apakah yang akan berlaku kepada arus dalam gegelung sekunder sekiranya
voltan sekunder dikurangkan kepada 6 V?
What will happen to current flows in secondary coil if its voltage being
decreased to 6 V?

[1 markah]
[1 mark]

MPP3 15 AKRAM JPNT

KELANTAN

r
KEDAH
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