Previous Year Question

Correct answer: D — It minimizes the reactive power burden on generators and transmission equipment.

Why low power factor burdens the network

An inductive load draws active power P to perform useful work and reactive power Q to maintain its electromagnetic fields. The supply equipment must carry the resulting apparent power S, even though reactive power does not represent net energy converted into useful work over a full AC cycle.

Power-factor improvement supplies part of the reactive requirement locally, for example through a capacitor bank. This reduces the net reactive power demanded from the upstream network while the useful active-power requirement can remain unchanged.

Effect on current and equipment capacity

At fixed active power and voltage, a higher power factor means a smaller line current. The lower current reduces I²R losses, reduces the current-related voltage drop and releases some of the kVA capacity of generators, transformers and lines.

For illustration, a 100 kW load requires 125 kVA at 0.8 power factor but only about 105.3 kVA at 0.95 power factor. Its active-power requirement remains 100 kW; the supply carries less apparent power because the reactive component is smaller. This is the meaning of reducing the reactive-power burden in option D. Compensation should match the load rather than create unnecessary leading VARs.