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Wire length, cross-section and resistivity

Change wire length and cross-section to compare resistance. Identical shapes can have different resistance depending on the material.

    E05 · Wire length, cross-section and resistivity0.00 s · Ready

    Electronics · DC circuits / Principles and inquiry

    Wire length, cross-section and resistivity experiment guide

    Change wire length and cross-section to compare resistance. Identical shapes can have different resistance depending on the material.

    How does it work?

    Doubling the length doubles resistance; doubling the cross-section halves it.

    Key relationship

    R = ρL/A · ρ = RA/L

    Try this investigation

    1. Change length and cross-section while watching the wire shape and resistance meter.
    2. Run and record each of the three baseline presets.
    3. At a length of 1 m, change only the cross-section or material.

    Interpreting your results

    With length and material fixed, what happens to resistance when area increases from 0.5 mm² to 1 mm²?

    R/2

    Assumptions and limitations

    Assume a uniform wire at 20 °C. Contact resistance, heating and temperature changes are omitted. Use this simulation; do not reproduce it with real power supplies or wall outlets.