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MODUL • Fizik TINGKATAN 5

Kesan medan elektrik ke atas cas / Effects of an electric field on charges

Bekalan kuasa voltan lampau tinggi (VLT) dihidupkan. Bola Bekalan kuasa VLT dihidupkan. Terangkan apa akan
pingpong dibawa bersentuhan dengan plat X dan dilepaskan. berlaku kepada nyalaan api lilin selepas beberapa ketika.
Terangkan apa yang akan berlaku kepada bola pingpong itu. EHT power supply is turned on. Explain what will happen to
Extra high tension (EHT) power supply is turned on. Ping-pong the candle flame after a while.
ball brought into contact with plate X and released. Explain what Bekalan kuasa voltan
will happen to the ping-pong ball. lampau tinggi (VLT)
Extra high tension Api lilin
Benang nilon power supply (EHT) Candle flame
Bekalan kuasa voltan Nylon thread
lampau tinggi (VLT)
Extra high tension Plat X
power supply (EHT) Plate X
Bola pingpong Lilin
yang disaluti Candle
cat logam –
Ping-pong ball +
coated with
metallic paint
+ – • Molekul udara di ionkan oleh haba daripada nyalaan
Plat Y lilin. / The molecules are ionised by heat of the flame.
Plate Y UNIT 2
+ -
• Bola pingpong menyentuh plat X, ia dicaskan positif. Plat terminal + - Plat terminal
UNIT 2
Ping-pong ball touches the plate X, it is positively charged. negatif + - positif
Negative
• Cas positif yang sama menolak bola pingpong ke plat terminal plate + - Positive
terminal plate
Y. The same positively charge repels the ping-pong balls to
plate Y. • Menghasilkan ion positif dan ion negatif.
• Bola pingpong menyentuh plat Y, ia dicaskan negatif. Produces positive and negative ions.
Ping-pong ball touches the plate Y, it is negatively charged. • Jisim ion positif molekul udara > jisim ion negatif
• Cas negatif yang sama menolak molekul udara. / Mass of positive ions of air molecules
bola pingpong ke plat X. > mass of negative ions of air molecules.
The same negatively charge repels • Ion-ion positif molekul udara ditarik ke plat negatif
the ping-pong balls to plate X. Video dengan perlahan. / The positive ions of air molecules are
• Bola pingpong berayun secara pulled towards the negative plate slowly.
berterusan di antara plat X dan • Ion-ion negatif molekul udara ditarik ke plat positif
plat Y. dengan cepat. / The negative ions of air molecules are
The ping-pong ball oscillates pulled towards the positive plate faster.
continuously in between plate X • Nyalaan lilin terbahagi kepada dua bahagian berlainan
and plate Y. Medan Elektrik saiz. / Flame of candle splits into two parts of different
Electric Field
https://goo.gl/rymXdV sizes.

Latihan / Exercise

1 Bateri sebuah kereta boleh membekalkan arus sebanyak 2 Arus 2 A mengalir melalui perintang. Apakah bilangan
6 A dalam masa 3 jam. Berapakah jumlah cas yang elektron yang mengalir melalui perintang dalam masa 5
disimpan di dalam bateri? saat? (cas elektron = 1.6 × 10 C)
–19
A car battery can supply a current of 6 A for 3 hours. What is A current of 2 A flows through a resistor. What is the number of
the amount of charge stored in the battery? electrons that have passed through the resistor in 5 seconds?
Penyelesaian / Solution (electron charge = 1.6 × 10 –19 C)
Penyelesaian / Solution
Q = It = 6 A × (3 × 60 × 60 s)
= 64 800 C Q = It, Q = ne
It = ne
n = 2 A × 5 s = 6.25 × 10 19
1.6 × 10 –19 C
\ Bilangan elektron / No. of electrons = 6.25 × 10 19

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