# Wiedemann-Franz law demonstration in a student practicum

## TL;DR

This paper presents a simple educational experiment demonstrating the Wiedemann-Franz law, which relates thermal and electrical conductivities in metals, to help students understand fundamental electronic properties.

## Contribution

It introduces an accessible experimental setup for verifying the Wiedemann-Franz law in a teaching context, facilitating practical understanding of electronic theory.

## Key findings

- Verification of the Wiedemann-Franz law in a classroom setting
- Educational demonstration of the Lorenz ratio as a universal constant
- Practical approach for teaching electronic conductivity concepts

## Abstract

Wiedemann-Franz law is a prediction of electronic theory of electric and thermal conductivity in metals, which states that a Lorenz ratio $L=\kappa/(\sigma T)$, where $\kappa$ is a thermal conductivity, $\sigma$ --- electric conductivity and $T$ --- absolute temperature, is a universal constant in certain cases. We present here a simple experimental setup to verify this prediction in a teaching experiment.