Identify the function of a capacitor.

• A. Works in conjunction with a reclosure
• B. Reduce voltage
• C. Protects substation and sub-transformer from overloads
• D. Added to system to improve power factor

Answer: (D)

Capacitors provide reactive power to offset inductive loads, which improves the power factor. By supplying leading reactive power, they cancel some of the lagging reactive power drawn by motors and transformers, so the current needed for the same real power is reduced. That smaller current lowers I^2R losses and frees up system capacity, and it also helps with voltage stability on the line. The other options describe protective devices, voltage reduction, or overload protection, which are not the primary role of a capacitor.