This document discusses electrical circuits and their components. It defines electric current as the flow of electrons in a conductor. Current flows from the negative terminal to the positive terminal in a circuit. A simple circuit contains a cell, bulb, and switch connected by wires. When the switch is closed, current can flow in a complete loop, lighting the bulb. Circuit diagrams use symbols to represent components like cells, bulbs, switches, and ammeters. Circuits can be connected in series, with one path for current, or in parallel, with multiple paths. Ammeters measure current by being placed in series, while voltmeters measure voltage by being placed across components.

1. ELECTRICAL CIRCUITS

2. What is an electric current?
o Aliran elektron berterusan membentuk arus elektrik
o Kekuatan arus elektrik begantung kepada kuantiti elektron
yang mengalir dalam unit masa
o Oleh itu, arus elektrik ditakrif sebagai kadar aliran elektron
dalam suatu konduktor
+
-
In which direction does the current flow?
from the Negative terminal to the Positive terminal of a
cell.

3. Litar Ringkas
-Mengandungi sel, mentol dan suis yang disambung
dengan wayar penyambung
sel
mentol
suis
Wayar
penyambung

4. simple circuits
When the switch is closed, the lamp lights up. This is
because there is a continuous path of metal for the
electric current to flow around.
If there were any breaks in the circuit, the current
could not flow.

5. circuit diagram
Melukis litar elektrik menggunakan simbol
Sel
kering
mentol suis wayar

6. circuit diagrams
In circuit diagrams components are represented by
the following symbols;
cell battery switch lamp
ammeter voltmeter motor
buzzer
resistor variable
resistor
Fius ?

7. Litar Selari dan Bersiri
Litar bersiri Litar selari

8. Litar Bersiri
Litar lengkap yang laluan sehala untuk arus elektrik
Setiap komponen di dalam litar disambungkan hujung
.ke hujung untuk membentuk satu laluan
If one bulb ‘blows’ it breaks the whole circuit and
all the bulbs go out.

9. Litar selari
Litar lengkap yang mempunyai dua atau lebih laluan untuk
arus elektrik mengalir
If one bulb ‘blows’ there is still be a complete circuit to
the other bulb so it stays alight.

10. Litar selari

11. Mengukur Arus
Diukur dalam unit ampere (A) dengan menggunakan
ammeter yang disambung secara bersiri dalam litar.
A

12. Mengukur Arus
This is how we draw an ammeter in a circuit.
A
A
SERIES CIRCUIT PARALLEL CIRCUIT

13. Mengukur Arus
SERIES CIRCUIT
• current is the same
at all points in the
circuit.
PARALLEL CIRCUIT
2A 2A
2A
• current is shared
between the
components
2A 2A
1A
1A

14. copy the following circuits and fill in the
missing ammeter readings.
?
?
4A
4A
4A
? 3A
1A
?
1A
?
3A
1A

15. Mengukur voltan
Daya elektrik diperlukan untuk menggerakkan cas
elektrik dari satu titik ke titik yang lain dikenali sebagai
voltan. Ia diukur dalam unit volts (V) menggunakan
voltmeter
V

16. Mengukur voltan
Different cells produce different voltages. The
bigger the voltage supplied by the cell, the bigger the
current.
Unlike an ammeter a voltmeter is connected across
the components

17. Mengukur voltan
This is how we draw a voltmeter in a circuit.
V
V
SERIES CIRCUIT PARALLEL CIRCUIT

18. V
Mengukur voltan
V
V
V

19. Litar bersiri
• voltage is shared between the components
1.5V
1.5V
3V

20. Litar selari
• voltage is the same in all parts of the circuit.
3V
3V
3V

21. measuring current & voltage
6V
V V
4A
A
A
a)

22. measuring current & voltage
6V
4A A
V
V
A
A
b)

23. answers
a) b)
6V
4A 4A
3V 3V
6V
4A 4A
6V
6V
2A
2A
4A