Electricity in the home Flashcards
The electric current repeatedly changes in direction
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The plug in the UK is a source of alternating current
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The mains electricity supply in the UK is 50hz and about 230 V
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The direct current meaning the current flows in one direction
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Batteries and cells are sources of direct current
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Earth wire has a green and yellow strip
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The earth wire only carries a current if there is a fault and is a safety wire to stop the appliance from becoming live
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The neutral wire is blue and it completes the circuit carrying the current away from the appliance
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The live wire is brown and carries a 230 V potential and it provides the alternating potential difference form the mains electricity supply
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power= potential difference x current
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energy transferred= power x time
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The National Grid is the network of transformers and cables that connect power stations with houses and shops in the UK
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Power stations create an electric current which is an energy carrier
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Power Stations produce electricity at a voltage of 25 000 volts
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Fuses and Circuit breakers protect us from electrical appliances by stooping the flow of electric current flow get too high. This stops the appliance from overheating
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Fuses contain a thin wire that melts if a current flowing through an appliance is too high as this breaks the circuit and stops the flow of electric current
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To select an appropriate fuse you need to have the potential difference of the power supply, the power label and the equation for power
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An earth wire is a low resistance wire that connects the metal case to the ground
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Because the resistance of the wire is low a very high current will flow through it breaking the fuse in the device. This will stop the flow of the current making the appliance safe
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The purpose of an earth wire is to make a faulty appliance safe
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Live Wires carry a large amount of electrical energy so they can be dangerous
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A love wire can still be dangerous even if the switch is off as it may still hold some potential difference
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A live wire and an earth wire can never be in contact as this would remove he safety feature of the earth wire
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