The power factor of an AC circuit having resistance R and inductance L connected in series and an angular velocity $\mathrm{\omega }$ is

• A

  $\mathrm{R}/\mathrm{\omega L}$

• B

  $\mathrm{R}/{\left({\mathrm{R}}^2+{\mathrm{\omega }}^2{\mathrm{L}}^2\right)}^{1/2}$

• C

  $\mathrm{\omega L}/\mathrm{R}$

• D

  $\mathrm{R}/{\left({\mathrm{R}}^2-{\mathrm{\omega }}^2{\mathrm{L}}^2\right)}^{1/2}$