If you improve power factor in a circuit delivering a fixed real power, what happens to current?

If you improve power factor in a circuit delivering a fixed real power, what happens to current?

• A. It increases current
• B. It reduces current
• C. It reverses current direction
• D. It has no effect

Answer: (B)

Power factor describes how much of the current is doing useful work versus circulating reactively. For a fixed real power and a fixed voltage, the current must adjust so that P = V_rms × I_rms × cos(phi). If you improve the power factor, cos(phi) increases, so I_rms must decrease to keep P the same. In other words, reducing the reactive part of the current means less total current is drawn from the source, delivering the same real power. The current doesn’t reverse direction, and there is a real change in current as PF improves.

Power factor describes how much of the current is doing useful work versus circulating reactively. For a fixed real power and a fixed voltage, the current must adjust so that P = V_rms × I_rms × cos(phi). If you improve the power factor, cos(phi) increases, so I_rms must decrease to keep P the same. In other words, reducing the reactive part of the current means less total current is drawn from the source, delivering the same real power. The current doesn’t reverse direction, and there is a real change in current as PF improves.