Question

For a series LCR circuit, at the condition of resonance, the value of the power factor will be:

• A. Zero
• B. 1
• C. 0.2
• D. 0.5

Answer 1

The Correct Option is B

Resonance in a series LCR circuit is achieved when inductive reactance matches capacitive reactance, resulting in their mutual cancellation. Consequently, the circuit's impedance becomes purely resistive. The power factor (PF), calculated as the cosine of the phase angle (ϕ) between voltage and current, is expressed as:

Power Factor \( (PF) = cos(ϕ) \)

At resonance, the phase difference ϕ is 0, indicating that current and voltage are in phase. This simplifies the power factor to:

\( PF = cos(0) = 1 \)

Thus, under resonance conditions in a series LCR circuit, the power factor equals 1.