An R-L Series AC circuit is a type of electrical circuit that consists of a resistor (R) and an inductor (L) connected in series to an alternating current (AC) voltage source. In this circuit, the alternating voltage source can be either a sinusoidal voltage or a complex waveform, and the circuit elements, the resistor and the inductor, respond to the changing voltage in their characteristic ways.
Let's break down the behavior of each component in an R-L series AC circuit:
Resistor (R):
A resistor is a passive component that offers a constant resistance to the flow of current. In an AC circuit, the voltage across the resistor and the current through it are in phase. This means that they rise and fall together as the AC voltage changes polarity. The relationship between voltage (V_R) across the resistor, current (I) through the resistor, and resistance (R) is given by Ohm's law: V_R = I * R.
Inductor (L):
An inductor is a passive component that stores energy in its magnetic field when current flows through it. In an AC circuit, the voltage across the inductor and the current through it are out of phase by 90 degrees. This phase difference causes the inductor to oppose changes in current, resulting in a delay in the rise and fall of current compared to the applied voltage. The relationship between voltage (V_L) across the inductor, current (I) through the inductor, inductance (L), and angular frequency (Ď) of the AC source is given by: V_L = I * Ď * L.
In an R-L series AC circuit, the total impedance (Z) is the vector sum of the impedance due to the resistor (Z_R = R) and the impedance due to the inductor (Z_L = jĎL, where j is the imaginary unit). Therefore, the total impedance Z is given by Z = R + jĎL.
The total current (I) flowing through the circuit is determined by the applied voltage (V) and the total impedance (Z) and can be calculated using Ohm's law: I = V / Z.
Since the resistor and the inductor have different phase relationships with the voltage, the total current in the circuit will also have a phase angle with respect to the applied voltage. This phase angle depends on the values of R, L, and the frequency of the AC source.
In summary, an R-L series AC circuit exhibits characteristics such as impedance, phase shifts between current and voltage, and energy storage due to the inductor. These properties have practical applications in various fields, including electronics, power distribution, and signal processing.