Question

In a circuit where current lags voltage, which ratio gives the power factor?

Options

• \[\cos\phi=\frac{I_p}{R}\]

• \[\cos\phi=\frac{I_q}{I_p}\]

• \[\cos\phi=\frac{R}{Z}\]

• \[\cos\phi=\frac{Z}{R}\]

Answer 1

The power factor is \[R/Z\]. Making the impedance \[Z\] tend toward the resistance \[R\] improves the power factor toward one.