What is generally done to improve the power factor of a circuit containing an inductive load such as a motor?

Answer: A. Connect a capacitor in parallel with the load

In an inductive load the current lags the voltage, producing lagging reactive power. A capacitor produces reactive power of the opposite (leading) sign, so placing one in parallel with the load cancels reactive power, reduces the current drawn from the supply and brings the power factor closer to 1. The voltage across the load and the active power it consumes are unchanged. Such power-factor-correction capacitors are used in factory power-receiving equipment, but overcompensation makes the power factor leading and can raise the voltage.

• A. Correct. The capacitor's leading reactive power cancels the load's lagging reactive power.
• B. Adding an inductor increases lagging reactive power and lowers the power factor further.
• C. Inductive reactance grows with frequency, so the power factor would get worse.