1 2
&
SERIES circuits : PARALLEL Circuits :
variab
-
↑
o O open switch 1 -
Rule for current (1)
resis
1 Rule for current (1) : 1 :
+
11 In Iz = = T
+
11 In =
12 Iz + =
14 >
~ o o closed switch--thermis
J
-
3 L
Fi ~ Is 10 8 A
.
o SA.
When current
A
>
- cel diode
The current is A 4 arrives at a branch/
> < = 1 -r D
I
junction it . The
splits
in all parts
,
equal each branch da
-
current in
LDR
-l-ft battery
-
-
T M
x
AX .
of the circuit
-
↑ titati A
Iz
A3 .
X
D LED
2 Rule for p d (v) : 0 4A -X-lamp/bulb
v3oUs
.
. .
.
=
U Uz2 Ruleforpd
+
(V) A-ammete
-3 # fuse
.
-
-
v
= J
Vs =
V1 =
Vz Electrical field close to a negative sphere Electrical field close to a positive sphere -
resistor (fixed - v-voltme
-
or
-3 The p d across each
3
.
4
. .
X X branch is equal to OHMIC (does not follo
#
-
L X the pd
.
.
of the source conductor NON-O
si
00 V
V
3 -sor [
-
.
2
↓ conduc
S
1
41
.
. 50
Vz t fixed resistor
-
[
The p d . .
of the source is the sum o I
X <
the p d across the components (shared) t
aI filament lamp
I
. . -
[
Rule for resistance (R) :
- -
3 [ aI
3 Rule for resistance (R) :
- I"
-
[
T
[
Im [
-
[ > V
Rtotal R1 + Rz =
...
Rtotal = lowest
resistance
[ > V
52 31
W
Ra
Ra R2 Electrical field between two opposite Electrical field between two parallel plates -
follows W
charges with opposite charges
The total resistance is the sum of Ohm's Law
resistor R2
the resistance ofeach
.
At a constant temperature, current
The total resistance is lower than through an ohmic conductor is directly
the smallest individual resistor.
proportional to potential difference
ELECTRICITY
(alternating current)
& a C supply electrons constantly change direction >
-
F
-
. .
-
↑
d C supply -
> electrons move in the same direction
↓
. .
-
(direct current) UK Mains supply is a C
. .
& ↳
p d
. .
=
24OV
frequency =
50thz
T
-
THE UKPLUG : EARTH wire
E
↳ current only flows
through
there is a
[
if faultin the
NEUTRALwire
8
i
·
appliance
2 own
-O
Y ↳ OV : stops
appliance casing -up
former c
completes the
ouer
transformer
↳
&
D
m
I
& *
u
-
an-
station
circuit (route for the becoming live (safety E
a c . . current) area -
a
↑ -
↑
-&
FUSE -
> melts if current
P S S
E
↳ at or close to earth - me
potential go LIVE wine " high
The National Grid is a