Factors On Which The Resistance Of A Conductor Depends

Key Notes:

Length of the Conductor:

• Resistance is directly proportional to the length of the conductor.
• The longer the conductor, the more resistance it offers to the flow of electric current.

R ∝ L

Cross-Sectional Area of the Conductor:

• Resistance is inversely proportional to the cross-sectional area.
• A conductor with a larger cross-sectional area has less resistance, allowing current to flow more easily.

R ∝ 1/A

Material of the Conductor:

• Different materials have different resistivities.
• Conductors like copper or silver have low resistivity and, therefore, low resistance, while materials like rubber or plastic have high resistivity and high resistance.
• Resistivity is denoted by ρ, and the resistance R depends on the material’s intrinsic property.

Temperature:

• For most conductors, resistance increases with an increase in temperature.

• As the temperature rises, atoms in the conductor vibrate more, causing more collisions between electrons and atoms, which increases resistance.

Formula for Resistance:

• The resistance R of a conductor is given by the formula:

R = ρ L/A

• R is the resistance,
• ρ is the resistivity of the material,
• L is the length of the conductor,
• A is the cross-sectional area.

Let’s practice!