Physics

8.6 - Resistance, Thickness & Material

1 min

note 1 of 1

How cross-section and material affect resistance

The resistance of a wire depends on its cross-sectional area and the material it's made from, as well as its length.
These are investigated using a test-wire set-up, changing one factor at a time while keeping the others fixed:
- Cross-sectional area - Use wires of the same material and length but different thicknesses. The thicker the wire (larger cross-sectional area), the lower its resistance.
- Material - Use wires of the same length and cross-sectional area but made of different metals. Different materials have different resistances because their conductivity differs.
In each case, measure current and potential difference to calculate resistance, keeping the current low so the wire stays at a constant temperature.

end of notes

Physics

1 min

note 1 of 1

The resistance of a wire depends on its cross-sectional area and the material it's made from, as well as its length.
These are investigated using a test-wire set-up, changing one factor at a time while keeping the others fixed:
- Cross-sectional area - Use wires of the same material and length but different thicknesses. The thicker the wire (larger cross-sectional area), the lower its resistance.
- Material - Use wires of the same length and cross-sectional area but made of different metals. Different materials have different resistances because their conductivity differs.
In each case, measure current and potential difference to calculate resistance, keeping the current low so the wire stays at a constant temperature.

end of notes