Which electrical component restricts current flow?

The component that restricts current flow is a resistor. Resistors are designed specifically to oppose the flow of electric current, which results in a drop in voltage. This opposition to current is measured in ohms, and it follows Ohm's Law, which states that the current through a conductor between two points is directly proportional to the voltage across the two points and inversely proportional to the resistance of the conductor.

In practical applications, resistors can be used to control the amount of current in a circuit, protect sensitive components from too much current, and divide voltages among different circuit elements. Resistors can be found in a variety of circuits and are essential for managing and directing electrical flow effectively.

Other components like capacitors, inductors, and transformers serve different purposes. Capacitors store electrical energy in an electric field, inductors store energy in a magnetic field, and transformers transfer electrical energy between two or more circuits through magnetic induction, but none of these components primarily act to restrict current flow as resistors do.