Name the rule for splitting conductor resistivity into temperature-independent and temperature-dependent parts In solid-state physics and electrical engineering, the empirical rule that expresses total resistivity of a metal as the sum of a temperature-independent term (residual) and a temperature-dependent phonon term is called:

Introduction / Context:
Metals exhibit electrical resistivity arising from multiple scattering mechanisms. For design and diagnostics (e.g., purity assessment or cryogenic wiring), engineers separate resistivity into temperature-independent and temperature-dependent components. Recognizing the canonical name of this decomposition is a basic competency.

Given Data / Assumptions:

• Total resistivity ρ ≈ ρi + ρT, where ρi is residual due to impurities/defects and ρT is mainly phonon scattering.
• Applies best when scattering mechanisms are independent and additive in effect.

Concept / Approach:

The empirical statement that different scattering contributions add to yield the total resistivity is known as Matthiessen's rule. While approximate, it provides a practical framework over wide temperature ranges except where strong interactions or saturation effects appear.

Step-by-Step Solution:

Verification / Alternative check:

Experimental plots of ρ(T) for high-purity metals approach ρi as T → 0 K and increase approximately linearly with T at higher temperatures, consistent with Matthiessen's form.

Why Other Options Are Wrong:

Debye relates to heat capacity/phonons; Curie to magnetic susceptibility; Onnes is associated with superconductivity observations; the last option is not the accepted name in resistivity splitting.

Common Pitfalls:

Over-applying the rule near phase transitions or where electron–electron scattering is significant.

Final Answer:

Matthiessen's rule