In an $LCR$ series $AC$ circuit at resonance,the value of the power factor will be . . . . . . .

In an $LCR$ circuit,the resonance frequency of the circuit increases to two times its initial value by changing the capacitance from $C$ to $C^{\prime}$ and the resistance from $100 \ \Omega$ to $400 \ \Omega$,while the inductance $L$ is kept constant. The ratio $C / C^{\prime}$ is:

Power factor is maximum in an $LCR$ circuit when

In a series $LCR$ resonant circuit,$R = 800 \ \Omega$,$C = 2 \ \mu F$,and the voltage across the resistance is $200 \ V$. The angular frequency is $250 \ rad/s$. At resonance,the voltage across the inductance is: (in $V$)

The power factor in an $L-C-R$ circuit at resonance is

$A$ parallel plate capacitor in series with a resistance of $100 \Omega$, an inductor of $20 \text{ mH}$, and an $AC$ voltage source of variable frequency shows resonance at a frequency of $\frac{1250}{\pi} \text{ Hz}$. If this capacitor is charged by a $DC$ voltage source to a voltage of $25 \text{ V}$, what amount of charge will be stored in each plate of the capacitor?