What is the purpose of a resistor in an electrical circuit?

The purpose of a resistor in an electrical circuit is to limit the flow of electric current. When a voltage is applied across a resistor, it creates a defined opposition to the current flowing through it, which is described by Ohm's Law (V = IR, where V is voltage, I is current, and R is resistance). This controlled resistance allows for the safe operation of various circuit components by ensuring that the current does not exceed certain levels that could potentially cause damage or malfunction.

Resistors are essential in many applications, including setting biasing levels for transistors, creating voltage dividers, and controlling signal levels in digital and analog circuits. By using resistors effectively, designers can manage current flow and help maintain the proper functioning of the circuit as a whole.

Other options do not accurately reflect the primary function of a resistor. Storing energy is a characteristic of capacitors or inductors, while amplifying signals is typically done by transistors or operational amplifiers. The conversion of DC to AC is handled by devices such as inverters, not resistors.