What is the phase difference between current and voltage in an AC circuit?

The phase difference between current and voltage in an AC (Alternating Current) circuit depends on the type of components present:

• Pure Resistor (R): The current and voltage are in phase, meaning the phase difference is 0°.
• Pure Inductor (L): The current lags behind the voltage by 90° (π/2 radians).
• Pure Capacitor (C): The current leads the voltage by 90° (π/2 radians).
• RLC Circuit: The phase difference can vary between -90° and +90°, depending on the relative values of resistance (R), inductance (L), and capacitance (C).
  • If inductive reactance > capacitive reactance, current lags.
  • If capacitive reactance > inductive reactance, current leads.
  • If they are equal (resonance), the current and voltage are in phase (0° phase difference).

This phase relationship is crucial for understanding power consumption, impedance, and energy transfer in AC circuits.