The correct answer is A. 0%.
At series or parallel resonance, the circuit impedance is purely resistive, and the current and voltage are in phase. This means that the power factor is 1.
The power factor is a measure of how efficiently electrical energy is being used in a circuit. It is defined as the ratio of the real power to the apparent power. The real power is the power that is actually used to do work, while the apparent power is the product of the voltage and current.
In a purely resistive circuit, the voltage and current are in phase, and the power factor is 1. However, in a reactive circuit, the voltage and current are out of phase, and the power factor is less than 1.
The power factor can be improved by using capacitors or inductors to cancel out the reactive components of the circuit. This is known as power factor correction.
Here is a brief explanation of each option:
- Option A: 0%. This is the correct answer. At series or parallel resonance, the circuit impedance is purely resistive, and the current and voltage are in phase. This means that the power factor is 1.
- Option B: 5%. This is not the correct answer. The power factor is not 5% at series or parallel resonance.
- Option C: 10%. This is not the correct answer. The power factor is not 10% at series or parallel resonance.
- Option D: 8%. This is not the correct answer. The power factor is not 8% at series or parallel resonance.