Mains supply is ac, Battery supply is dc

There are two types of electricity supplies- alternating current(ac) and direct current(dc)
In ac supplies the current is constantly changing direction. Alternating currents are produced by alternating voltages in which the positive and negative ends keep alternating
The UK mains supply is an ac supply at around 50Hz
By contrast, cells and batteries supply direct current
Direct current is a current that is always flowing in the same direction. It’s created by a direct voltage.

Most cables have Three Separate Wires

Most electrical appliances are connected to the mains supply by three-core cables. This means that they have three wires inside them, each with a core of copper and a coloured plastic coating.
The colour of the insulation on each cable shows its purpose
The colours are always the same for every appliance. This is so that it is easy to tell the different wires apart.
You need to know the colour of each wire, what each of them is for and what their pd is:
LIVE WIRE=brown. The live wire provides the alternating potential difference(about 230V) from the mains supply
NEUTRAL WIRE=blue. The neutral wire completes the circuit-when the appliance is operating normally, current flows through the live and neutral wires, at 0V
EARTH WIRE=green and yellow. It is for protecting the wiring, and for safety-it stops the appliance casing from becoming live. It doesn’t usually carry a current-only when there’s a fault. It’s also at 0V

You body is at 0V. This means that if you touch the live wire-a large potential difference is produced across your body and a current flows through you.
This causes a large electric shock which could injure or even kill you
Even if a plug socket or a light switch is turned off there is still a danger of an electric shock. A current isn’t flowing but there’s still a pd in the live wire. If you made contact with the live wire, your body would provide a link between the supply and the earth, so a current would flow through your body
Any connection between live and earth can be dangerous. If the link creates a low resistance path to earth, a huge current will flow, which could result in a fire.

There are two types of electricity supplies- alternating current(ac) and direct current(dc)
In ac supplies the current is constantly changing direction. Alternating currents are produced by alternating voltages in which the positive and negative ends keep alternating
The UK mains supply is an ac supply at around 50Hz
By contrast, cells and batteries supply direct current
Direct current is a current that is always flowing in the same direction. It’s created by a direct voltage.

Most electrical appliances are connected to the mains supply by three-core cables. This means that they have three wires inside them, each with a core of copper and a coloured plastic coating.
The colour of the insulation on each cable shows its purpose
The colours are always the same for every appliance. This is so that it is easy to tell the different wires apart.
You need to know the colour of each wire, what each of them is for and what their pd is:
LIVE WIRE=brown. The live wire provides the alternating potential difference(about 230V) from the mains supply
NEUTRAL WIRE=blue. The neutral wire completes the circuit-when the appliance is operating normally, current flows through the live and neutral wires, at 0V
EARTH WIRE=green and yellow. It is for protecting the wiring, and for safety-it stops the appliance casing from becoming live. It doesn’t usually carry a current-only when there’s a fault. It’s also at 0V

You body is at 0V. This means that if you touch the live wire-a large potential difference is produced across your body and a current flows through you.
This causes a large electric shock which could injure or even kill you
Even if a plug socket or a light switch is turned off there is still a danger of an electric shock. A current isn’t flowing but there’s still a pd in the live wire. If you made contact with the live wire, your body would provide a link between the supply and the earth, so a current would flow through your body
Any connection between live and earth can be dangerous. If the link creates a low resistance path to earth, a huge current will flow, which could result in a fire.