Plastic materials are good insulators. An appliance that has a plastic case is double-insulated, so it has no earth wire connection.
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Card 8
Front
The longest pin of a three-pin plug is designed to make contact with the earth wire of a wall socket circuit. So, when you plug an appliance with a metal case into a wall socket, the case is automatically earthed.
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Card 9
Front
The case material is an electrical insulator. The inside of the case is shaped so that the wires and pins can't touch each other when the plug is sealed.
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Card 10
Front
The brown wire is connected to the live pin.
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Card 11
Front
The green and yellow striped wire is connected to the earth pin. A two-core cable doesn't have an earth wire.
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Card 12
Front
P5.3 - Electrical power and potential difference
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Card 13
Front
For any electrical appliance: the current through it is that flows through it each second.
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Card 14
Front
For any electrical appliance: the power supplied to it is the energy transferred to it each second. This is the energy transferred be an electric current every second.
Back
Card 15
Front
Domestic appliances are often fitted with a 3A, 5A, or a 13A.
