What are substances that resist the passage of an electric current called?

Substances that resist the passage of an electric current are known as insulators. This term describes materials that do not easily allow electrical charges to flow through them, making them effective in preventing the transfer of electricity. Insulators are used in a variety of applications, particularly in electrical wiring and equipment, to ensure safety and control the flow of current where it is needed.

In contrast, conductors are materials that allow electric current to pass through easily, making them the opposite of insulators. Electrolytes are substances that conduct electricity when dissolved in water or molten but generally involve ion movement instead of resisting current. Semiconductors have conductive properties that fall between conductors and insulators and can allow electric current under certain conditions, typically influenced by temperature or the presence of impurities.