Electricity in the home

Question 1

The electric current repeatedly changes in direction

Answer 1

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Question 2

The plug in the UK is a source of alternating current

Answer 2

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Question 3

The mains electricity supply in the UK is 50hz and about 230 V

Answer 3

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Question 4

The direct current meaning the current flows in one direction

Answer 4

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Question 5

Batteries and cells are sources of direct current

Answer 5

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Question 6

Earth wire has a green and yellow strip

Answer 6

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Question 7

The earth wire only carries a current if there is a fault and is a safety wire to stop the appliance from becoming live

Answer 7

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Question 8

The neutral wire is blue and it completes the circuit carrying the current away from the appliance

Answer 8

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Question 9

The live wire is brown and carries a 230 V potential and it provides the alternating potential difference form the mains electricity supply

Answer 9

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Question 10

power= potential difference x current

Answer 10

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Question 11

energy transferred= power x time

Answer 11

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Question 12

The National Grid is the network of transformers and cables that connect power stations with houses and shops in the UK

Answer 12

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Question 13

Power stations create an electric current which is an energy carrier

Answer 13

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Question 14

Power Stations produce electricity at a voltage of 25 000 volts

Answer 14

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Question 15

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

Answer 15

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Question 16

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

Answer 16

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Question 17

To select an appropriate fuse you need to have the potential difference of the power supply, the power label and the equation for power

Answer 17

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Question 18

An earth wire is a low resistance wire that connects the metal case to the ground

Answer 18

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Question 19

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

Answer 19

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Question 20

The purpose of an earth wire is to make a faulty appliance safe

Answer 20

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Question 21

Live Wires carry a large amount of electrical energy so they can be dangerous

Answer 21

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Question 22

A love wire can still be dangerous even if the switch is off as it may still hold some potential difference

Answer 22

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Question 23

A live wire and an earth wire can never be in contact as this would remove he safety feature of the earth wire

Answer 23

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