Ohmischer

Ohmischer is a German term used to describe electrical behavior that follows Ohm's law. In English, the corresponding adjective is ohmic. An ohmischer component or material exhibits a linear relationship between voltage and current, with a constant resistance, so that V = IR. This description holds for ranges of voltage and current where the resistance remains essentially unchanged by the operating conditions.

In practice, many metallic conductors and fixed-value resistors behave ohmisch within specified ranges. Deviations from ohmisch behavior occur in non-ohmic devices, such as diodes and transistors, and in components whose resistance changes with temperature, voltage, or magnetic fields. For example, a filament lamp becomes non-ohmic as it heats up and its resistance increases.

Key characteristics of ohmischer behavior include a straight-line V-I curve passing through the origin, a constant resistance equal to the slope of the V-I graph (dV/dI), and a predictable response to circuit changes. Limitations include the temperature coefficient of materials, impurities, and the breakdown of ohmic behavior under extreme currents, voltages, or rapidly changing conditions.

Etymology and usage: the term derives from Georg Simon Ohm, the physicist who formulated Ohm's law, with the German adjective form ohmisch or ohmischer reflecting phenomena related to Ohm's law. The English counterpart is typically simply "ohmic."