Resistivity of a conductor depends on

The correct answer is Option (2) → its material and temperature of the conductor

Resistance depends on the dimensions, but resistivity is a property of the material. The two are related by

    \( \displaystyle R = \rho\,\frac{l}{A} \)

Here the length \( l \) and the area \( A \) are the dimensions. They sit outside \( \rho \), so \( \rho \) does not depend on them. It does depend on the material (the electron density and the time between collisions) and on the temperature, which changes the collision time.

Option (1) its material and the dimensions of the conductor — Incorrect. The dimensions affect the resistance \( R \), not the resistivity \( \rho \).

Option (2) its material and temperature of the conductor — Correct. Resistivity is fixed by the material at a given temperature.

Option (3) the dimensions of the conductor only — Incorrect. Dimensions do not change the resistivity.

Option (4) the temperature of the conductor only — Incorrect. Different materials have different resistivities at the same temperature.

NCERT (2026-27):
Ohm’s Law – “… Combining Eqs. (3.5) and (3.7), we have

    \( \displaystyle R \propto \frac{l}{A} \qquad (3.8) \)

and hence for a given conductor

    \( \displaystyle R = \rho \frac{l}{A} \qquad (3.9) \)

where the constant of proportionality ρ depends on the material of the conductor but not on its dimensions. ρ is called resistivity.”

Temperature Dependence of Resistivity – “The resistivity of a material is found to be dependent on the temperature.”