Final answer:
The Wiedemann-Franz-Lorentz law shows that the ratio of thermal conductivity to electrical conductivity of a metal is proportional to its temperature, implying that good electrical conductors tend to be good thermal conductors as well.
Step-by-step explanation:
Wiedemann-Franz-Lorentz Law The Wiedemann-Franz-Lorentz law is a principle in physics that establishes a relationship between the thermal conductivity (k) and the electrical conductivity (σ) of metals. According to this law, the ratio of the thermal conductivity to the electrical conductivity of a metal is directly proportional to the temperature (T), expressed as:
k/σ = L × T
where L is a constant known as the Lorenz number and T is the absolute temperature in Kelvin.
This law indicates that good electrical conductors are typically also good thermal conductors. The underlying reason is that in metals, both the thermal and electrical conductivity are largely transported by free electrons. As such, the processes which make metals conductive of electricity also enable them to efficiently transmit heat.
The Wiedemann-Franz-Lorentz law aids in understanding the transport properties of conductive materials and how they evolve with temperature changes, which is an essential concept in material science and engineering applications.