Instrumentation (INS) Practice Test

Power factor equals which ratio?

The ratio of real power to reactive power. The ratio of apparent power to real power. The ratio of reactive power to apparent power. The ratio of real power to apparent power.

Correct Answer:

The ratio of real power to apparent power.

Explanation:

Power factor is the ratio of real power to apparent power, P over S. Real power (watts) is the actual energy used to do work, while apparent power (volt-amperes) is the product of RMS voltage and RMS current and includes the effects of reactive power stored in inductors and capacitors. The power factor also equals the cosine of the phase angle between voltage and current, so PF = cos(phi). This means it reaches 1 when voltage and current are perfectly in phase (purely resistive) and is less than 1 when reactive power is present.

Access more questions from this quiz

Continue to Instrumentation (INS) Practice Test for more practice questions and the full quiz experience.

Access More Questions