In which of the following $AC$ circuit, we get the value of power factor $1$ at resonance condition?

The $Q$-value of a series $LCR$ circuit with $L=2 \ H$,$C=32 \ \mu F$,and $R=20 \ \Omega$ is:

Obtain the resonant frequency and $Q$-factor of a series $LCR$ circuit with $L=3.0\; H$,$C=27\; \mu F$,and $R=7.4\; \Omega$. It is desired to improve the sharpness of the resonance of the circuit by reducing its 'full width at half maximum' by a factor of $2$. Suggest a suitable way.

In a series $LR$ circuit with $X_L = R$, the power factor is $P_1$. If a capacitor of capacitance $C$ with $X_C = X_L$ is added to the circuit, the power factor becomes $P_2$. The ratio of $P_1$ to $P_2$ will be:

The capacitor of an oscillatory circuit is enclosed in a container. When the container is evacuated,the resonance frequency of the circuit is $10\, kHz$. When the container is filled with a gas,the resonance frequency changes by $50\, Hz$. The dielectric constant of the gas is

What is the value of inductance $L$ for which the current is a maximum in a series $LCR$ circuit with $C=10 \mu F$ and $\omega=1000 \ s^{-1}$?