How can capacitor usage affect power factor in AC circuits?

How can capacitor usage affect power factor in AC circuits?

• A. Capacitors absorb leading current to offset lagging current, improving power factor.
• B. Capacitors eliminate current entirely.
• C. Capacitors store energy for short-term use.
• D. Capacitors supply leading current to offset lagging current, improving power factor.

Answer: (D)

Capacitors improve power factor by providing reactive power that leads the voltage. In AC circuits, power factor is the cosine of the phase angle between voltage and current. Inductive loads cause the current to lag the voltage, which lowers the power factor. A capacitor connected in parallel with the load supplies current that leads the voltage. By contributing this leading current, it partially cancels the lagging current from the inductive parts of the circuit, reducing the phase difference and raising the power factor toward 1. For example, if the load causes a 30-degree lag, the right amount of capacitance can bring the net lag down and boost the power factor accordingly. While capacitors do store energy in their electric field, their practical effect here is to offset the lagging current and improve efficiency, not to absorb leading current or eliminate current altogether.

Capacitors improve power factor by providing reactive power that leads the voltage. In AC circuits, power factor is the cosine of the phase angle between voltage and current. Inductive loads cause the current to lag the voltage, which lowers the power factor. A capacitor connected in parallel with the load supplies current that leads the voltage. By contributing this leading current, it partially cancels the lagging current from the inductive parts of the circuit, reducing the phase difference and raising the power factor toward 1. For example, if the load causes a 30-degree lag, the right amount of capacitance can bring the net lag down and boost the power factor accordingly. While capacitors do store energy in their electric field, their practical effect here is to offset the lagging current and improve efficiency, not to absorb leading current or eliminate current altogether.