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MODUL • Fizik TINGKATAN 5

Faktor yang mempengaruhi kecekapan transformer dan cara untuk meningkatkan kecekapannya
Factors that affect the efficiency of a transformer and ways to improve the efficiency

Punca kehilangan tenaga Cara mengatasi Sebab
Cause of energy loss Way to overcome Reason

Rintangan gegelung : Gunakan dawai kuprum tebal • Rintangan lebih rendah.
The resistance of coil : sebagai gegelung. Lower resistance.
• kesan pemanasan / the effect of heating Use thick copper wire as
• menghasilkan haba / heat is produced coil. • Mengurangkan penghasilan
• E = Q = I Rt haba .
2
To reduce the heat produce.
Kesan histerisis / Hysterisis effect Gunakan teras besi lembut. Besi lembut lebih mudah dimagnetkan dan
• Kehilangan tenaga semasa proses Use soft iron core. lebih mudah dinyah-magnetkan.
pemagnetan dan penyah-magnetan. Soft iron is easy to be magnetised and easy to
Loss of energy during the process of be demagnetised.
magnetisation and demagnetisation.
• Tenaga hilang dalam bentuk haba.
Energy is lost in form of heat.

Kebocoran fluks magnet . (i) Reka bentuk teras : Sambungan fluks magnet lebih baik antara
Design of core:
The leakage of magnetic flux . gegelung primer dan gegelung sekunder.
• Tenaga elektrik hilang kerana kehilangan (ii) Melilitkan gegelung sekunder di Better linkage of magnetic flux between the
sebahagian fluks magnet yang terhasil di atas gegelung primer. primary coil and the secondary coil.
gegelung primer. Wind the secondary coil on the top of
Electrical energy is lost due to loss a part the primary coil. UNIT 3
of the magnetic flux in the primary coil. (iii) Mengurangkan jarak antara
UNIT 3
• Menyebabkan d.g.e teraruh di gegelung gegelung sekunder dan gegelung
sekunder menjadi lebih kecil. primer.
Causing induced e.m.f in the secondary Reduce the distance between the
coil becomes smaller.
primary coil and the secondary coil.

Arus pusar dalam teras. Teras berlamina Menghasilkan haba arus
Eddy currents in the core. digunakan. pusar.
• Pemutaran elektron dalam teras Laminated core is used. To heat the eddy currents.
disebabkan medan magnet yang berubah-
ubah. / Rotation of electrons in the core as
magnetic field changing.

Latihan / Exercise

1 Bilangan lilitan dalam gegelung primer dan gegelung sekunder pada transfomer masing-masing ialah 50 dan 250. Apakah beza
keupayaan output apabila transformer menggunakan bekalan kuasa 12 V?
The number of turns in the primary and secondary coil of a transformer are 50 and 250 respectively. What is the output voltage when
the transformer is using a voltage of 12 V?
Penyelesaian / Solution
Diberi / Given N = 250 lilitan / turns, N = 50 lilitan / turns, V = 12 V
s p p
N s V s
=
N p V p
V = N s V p
s
N p
250 lilitan / turns × 12 V
= = 60 V
50 lilitan / turns

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