Which factor affects the impedance in an RL circuit when frequency is altered?

In an RL circuit, impedance is affected by both resistance and inductance. However, when the frequency of the source voltage is altered, it is primarily the inductance that plays a crucial role.

As frequency increases, the reactance of the inductor also increases, which is represented by the formula for inductive reactance: (X_L = 2\pi f L), where (f) is the frequency and (L) is the inductance. This means that at higher frequencies, the inductive reactance increases, leading to a greater total impedance in the circuit. Conversely, if the frequency decreases, the inductive reactance decreases, which lowers the total impedance.

Resistance, while present in the circuit, does not change with frequency; it remains constant regardless of how the frequency is altered. Capacitance is not a factor in an RL circuit since it pertains to circuits that include capacitors. Voltage can influence the overall power and current in the circuit but does not affect the impedance based on frequency.

Thus, the correct answer centers on the behavior of inductance with frequency change, demonstrating its significance in determining the overall impedance in an RL circuit.