What are factors that determine a conductor's resistance?

What are factors that determine a conductor's resistance?

• A. Conductor material, diameter, length, and temperature
• B. Conductor material only
• C. Diameter and length only
• D. Temperature only

Answer: (A)

Resistance in a conductor comes from how easily electrons can move through the material, which depends on four factors: the material’s intrinsic resistivity, the path length, the cross-sectional area of the path (related to diameter), and temperature. The material determines the baseline resistance through its resistivity: different substances offer different levels of opposition to current. The path length matters because resistance grows with length—double the length means roughly double the resistance. The cross-sectional area matters inversely: a wider path (larger diameter) provides more routes for electrons, lowering resistance, while a smaller diameter confines electrons and raises resistance. Temperature changes the material’s resistivity; for most metals, resistance increases as temperature rises, since atomic vibrations scatter electrons more. Putting it all together with the relation R = ρL/A helps see why all four factors are necessary: longer length increases resistance, larger diameter decreases it, the material sets the baseline through ρ, and temperature shifts ρ as well. If you only consider one or two of these aspects, you’d miss how the others also shape the overall resistance.

Resistance in a conductor comes from how easily electrons can move through the material, which depends on four factors: the material’s intrinsic resistivity, the path length, the cross-sectional area of the path (related to diameter), and temperature.

The material determines the baseline resistance through its resistivity: different substances offer different levels of opposition to current. The path length matters because resistance grows with length—double the length means roughly double the resistance. The cross-sectional area matters inversely: a wider path (larger diameter) provides more routes for electrons, lowering resistance, while a smaller diameter confines electrons and raises resistance. Temperature changes the material’s resistivity; for most metals, resistance increases as temperature rises, since atomic vibrations scatter electrons more.

Putting it all together with the relation R = ρL/A helps see why all four factors are necessary: longer length increases resistance, larger diameter decreases it, the material sets the baseline through ρ, and temperature shifts ρ as well. If you only consider one or two of these aspects, you’d miss how the others also shape the overall resistance.