Question

A series LCR circuit is tuned to resonance. If the angular frequency of the applied AC voltage at resonance is $\omega$, the impedance of the circuit then is:

• A. $R+\omega L+\left(\frac{1}{\omega C}\right)$
• B. R
• C. $\sqrt{R^2+\omega L+{\left(\frac{1}{\omega C}\right)}^2}$
• D. $\sqrt{R^2+{(\omega L-\frac{1}{\omega C})}^2}$

Answer 1

Answer: (B)

R

At resonance $\frac{1}{\omega C}=\omega L$

$\therefore impedance=R$