What electrical concept is defined as the opposition to current flow?

Resistance is the electrical concept that represents the opposition to current flow in a circuit. When an electric current passes through a conductor, such as a wire, resistance determines how much current will flow for a given voltage according to Ohm's Law (V = IR), where V is voltage, I is current, and R is resistance. The higher the resistance in a circuit, the lower the current flow for a given voltage.

Resistance is an intrinsic property of materials, influenced by factors such as material type, temperature, and physical dimensions. Conductors like copper have low resistance, allowing electricity to flow easily, while insulators, like rubber, have high resistance, preventing current flow. Understanding resistance is crucial for designing and working with electrical circuits, as it affects the efficiency and safety of the entire system.

In contrast, voltage refers to the electric potential difference that drives current through a circuit, capacitance measures a component's ability to store electric charge, and inductance pertains to the property of a conductor to oppose changes in current flow due to magnetic fields.