Reactive power is the component of power that contributes to maintaining voltage levels for system stability. Which option best describes this?

• A. Active power
• B. Reactive power
• C. Apparent power
• D. Harmonic power

Answer: (B)

The main idea is that electrical power has two parts: one does the actual work, and the other supports the voltage in the system. Reactive power is the portion that doesn’t do useful work itself but moves energy back and forth between the source and the loads through inductive and capacitive elements. This exchange is what helps keep voltage levels steady across the grid, contributing to system stability and proper voltage regulation. Real (active) power is the part that powers devices (it is in phase with voltage), while apparent power combines both real and reactive power into a single magnitude. Harmonic-related effects can distort voltages and currents but aren’t a standard component that maintains voltage like reactive power. So reactive power best describes the role of maintaining voltage levels for stability.