Typical Conductivity Values
3. Benchmarking Conductive and Non-Conductive Materials
While a specific “conductive” ohm value is elusive, we can look at the typical conductivity (or resistivity, which is the inverse) of different materials to get a sense of scale. Remember, lower resistance (or higher conductivity) means a better conductor. Resistivity is often expressed in ohm-meters (m).
Excellent Conductors: Copper is a workhorse in electrical wiring because of its high conductivity. Silver is even better, but its cost usually limits its use to specialized applications. Gold is also a good conductor and resistant to corrosion, making it ideal for connectors in electronics.
Semiconductors: Materials like silicon and germanium are semiconductors. Their conductivity falls between that of conductors and insulators, and it can be controlled by adding impurities (a process called doping). This control is what makes semiconductors essential components in transistors and integrated circuits.
Insulators: Materials like rubber, glass, and plastic are excellent insulators. They have very high resistance, preventing the flow of electricity. These materials are used to insulate wires and other electrical components, preventing short circuits and protecting us from electric shock.
Trying to define conductivity with a single number is akin to saying what height makes someone tall. A six-foot-tall person might be considered tall in some countries but average in others. Conductivity is relative, depending on the intended use case.