Electricity
Circuits
Symbols
Types
Series
Parallel
In short if one bulb pops
the others will still run ok
On one wire. If one goes the others
won't work because on the same circuit
An example of a series circuit is a string
of Christmas lights. If any one of the bulbs is missing or burned out, no current will flow and none of the lights will go on
More Letter Symbols
Q
Charge
Techy equations
PD
Potential Difference
I
Current
t
Time
Calculating current I = Q/t
Calculating energy transferred E = V × Q
E
Energy transferred in joules
V
Potential difference in volts
J
Joules
C
Coulans
Mains Electricity
Cables
Each wire is made has a plastic coating
They consist of three smaller wires ⁉
They are made of copper
Colour codes 🏳️🌈
Blue 🔵
Brown🟤
Green and Yellow 🟡🟢
Live
Neutral
Earth
Types current
AC
DC
AC is alternating current, a current which is constantly changing in direction.
DC is direct current, current that is always flowing in one direction.
Cells or batteries
Mains electricity (50Hz)
Electrical Surges
If there is a surge of electrical current in the mains supply this could damage any appliances or devices connected to the mains supply.
A lightning strike is a likely cause
Ways to protect against it
Fuses
Circuit breakers
Fuses
A fuse is a device that is used to protect
devices from a current which is too high.
How does a fuse work?💥
As current flows along a
conductor there is friction
between the electrons and
the atoms of the conductor.
If you have a lamp and it has a potential difference of 200V across it and it operates at a power of 60W:
Smelly Equations
Power is , it is measured in Watts
Energy is , it is measured in Joules
time is , it is measured in seconds
Voltmeters are in parallel
Ammeters are always connected in series
Ohms
current x resistance = volts