Physics

Problem

A series LR circuit is connected to an ac source of frequency

\omega

and the inductive reactance is equal to

2R

. A capacitance of capacitive reactance equal to

R

is added in series with

L

and

R

. What is the ratio of the new power factor to the old one? a.

\sqrt{\frac{2}{3}}

\sqrt{\frac{2}{5}}

\sqrt{\frac{3}{2}}

\sqrt{\frac{5}{2}}