What is the function of a resistor in an AC circuit?

A resistor in an AC circuit limits the flow of current and reduces the voltage.

Resistors are passive components that resist the flow of current in a circuit. In an AC circuit, the voltage and current are constantly changing direction and magnitude. The resistor limits the flow of current and reduces the voltage by converting electrical energy into heat energy. This is known as 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 between them.

In an AC circuit, the resistor can also affect the phase relationship between the voltage and current. The phase angle between the voltage and current is determined by the impedance of the circuit, which is the combination of resistance, capacitance, and inductance. The resistor only contributes to the resistance component of the impedance, but it can still affect the phase angle. If the resistor is in series with a capacitor or inductor, it can cause a phase shift in the voltage and current.

Overall, the function of a resistor in an AC circuit is to limit the flow of current and reduce the voltage, while also contributing to the impedance and phase relationship of the circuit. Resistors are commonly used in AC circuits for voltage dividers, current limiting, and signal conditioning.