Resistivity Dependence on Material

Resistivity is a fundamental property of a substance that quantifies how strongly it resists electric current. It is an intrinsic characteristic of the material itself.

The formula relating resistance ($R$), resistivity ($\rho$), length ($L$), and cross-sectional area ($A$) is given by:

$ R = \rho \frac{L}{A} $

Analysis of Factors

• Material: Resistivity ($\rho$) is inherent to the material. For example, copper has a much lower resistivity than rubber. This is the primary factor.
• Number of wires: This relates to quantity, not the intrinsic property of the material.
• Diameter of the wire: Diameter affects the cross-sectional area ($A$). While area influences resistance ($R$), it does not change the material's resistivity ($\rho$).
• Length of the wire: Length ($L$) directly influences resistance ($R$) but does not alter the resistivity ($\rho$) of the material.

Key Takeaway

Resistivity is solely dependent on the nature of the Material and, to some extent, temperature (though material is the main factor). Dimensions like length and diameter affect resistance, not resistivity.