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11 Cards in this Set
- Front
- Back
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What are the three things that determine resistance |
Length Area Resistivity |
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Length |
The longer the wire and the more difficult it is to make a current flow |
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Area |
The wider the wire the easier it will be for the electrons to pass along it |
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Resistivity |
(Depends in the material) The structure may make it easy/difficult for change to flow |
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What environmental factors does resistivity depend on |
Temperature and light intensity |
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Resistivity equation |
(Resistance x Area) / length |
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What is resistivity measured in |
Ohm metres |
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Method for resistivity of the wire |
Look at page 86 in revision guide |
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What is resistivity caused by |
Interaction of moving electrons (current) with fixed positive ions of the metal |
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What is resistivity caused by |
Interaction of moving electrons (current) with fixed positive ions of the metal |
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Resistivity as temperatures increases |
As temp increases, electrons lose more energy in these interactions, less collisions and the resistance increases Change in resistivity is proportional to change in temp in particular metals |
