What effect does temperature have on the inductance of a coil?

The inductance of a coil can indeed be influenced by temperature, as various physical properties of the materials involved change with temperature. At higher temperatures, the resistivity of the wire increases, which can affect the skin effect—this influences how the current distributes itself in the conductor. Additionally, magnetic materials used in the coil, if any, may experience changes in their permeability with temperature, which directly impacts inductance.

The combined effects of these changes result in a scenario where inductance can either increase or decrease depending on the material characteristics and the temperature range. For instance, if a coil's core material enters a state where it can no longer effectively support magnetic fields due to temperature rise, inductance may decrease. Conversely, if the temperature enhancement causes better conduction in certain setups, inductance could increase. This variability illustrates why it is accurate to assert that temperature can increase or decrease inductance.