How can power factor be improved in AC circuits?

• A. Increase reactive power
• B. Reduce reactive power
• C. Increase voltage
• D. Increase real power only

Answer: (B)

Power factor shows how much of the supplied power is doing useful work. It’s the ratio of real power (the work actually done) to apparent power, and the reactive power part of the current doesn’t contribute to that work. When reactive power is present, the current must be larger to get the same real power, which lowers the power factor.

Reducing reactive power lowers the amount of current needed for the same real power, so the current and voltage become more in sync and the angle between them shrinks. That pushes the power factor closer to 1, meaning more of the supplied power is being used effectively. In practice, this is done by adding capacitive elements to counteract inductive effects, supplying leading reactive power to cancel the lag from inductive loads.

Increasing reactive power would make the current larger and worsen the power factor. Merely increasing voltage doesn’t fix the phase relationship between voltage and current, and increasing real power without addressing reactive power doesn’t improve the factor unless you also reduce the reactive component.