What is the function of a resistor in a circuit?

A resistor's primary function in a circuit is to limit or regulate current flow. By providing resistance, it controls the amount of current that can pass through a circuit based on Ohm's law, which states that the current (I) through a conductor between two points is directly proportional to the voltage (V) across the two points and inversely proportional to the resistance (R). This regulation is crucial for protecting sensitive components from excessive current, ensuring they operate safely and efficiently within their intended parameters.

In contrast, storing electrical energy is a function associated with capacitors or inductors, which can hold energy temporarily in an electric field or magnetic field, respectively. Amplifying signals is typically done by transistors or operational amplifiers, not resistors. Converting AC to DC is a function specific to rectifiers or transformers, which change the nature of the current rather than just controlling its flow. Thus, the resistor's role in limiting and regulating current flow is essential for the proper functioning and protection of circuits in electronic devices.