I/V Characteristics

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The shallower the gadient on a V/I graph, the greater the resistance.

Here is a circuit that could be used to obtain an I/V graph for a componant.

Metallic Conductor

  • At constant temperature, the current through a metallic componant is directly proportional to the voltage.
  • Metallic conductors are ohmic. The resistance does not change providing the the temperature does not change.

Filament Lamp

  • The gradient of the graph starts steep but becomes shallower.
  • This is because, as current flows through the wire, the wire gets hot so the atoms begin to vibrate more, making it more difficult for the current to get through. Hence increasing the resistance.
  • The resistance of a metal increase as temperature…


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