- Specific resistance (\( \rho \)): The resistance offered by a unit length and unit cross-sectional area of a material. It is given by:
\[
\rho = R \cdot \frac{A}{l},
\]
where \( R \) is resistance, \( A \) is cross-sectional area, and \( l \) is the length.
- Conductance (\( G \)): The reciprocal of resistance. It is given by:
\[
G = \frac{1}{R}.
\]