The figure shows a combination of inductances and capacitances. The resonant frequency of the $L-C$ circuit is:

In a series $LR$ circuit,power of $400 \ W$ is dissipated from a source of $250 \ V, 50 \ Hz$. The power factor of the circuit is $0.8$. In order to bring the power factor to unity,a capacitor of value $C$ is added in series to the $L$ and $R$. Taking the value of $C$ as $(\frac{n}{3 \pi}) \mu F$,then the value of $n$ is $......$

Obtain the relation of phase between instantaneous current and voltage with the help of a phasor diagram for a series $LCR$ circuit.

An $L-C-R$ series circuit is connected to an $AC$ source of peak voltage $240 \ V$. The phase difference between voltage and current of this circuit is $45^{\circ}$ and the resistance is $100 \ \Omega$. The $rms$ value of current through the circuit is . . . . . . . (in $A$)

When $L$, $C$, and $R$ are connected in series with an $AC$ source of frequency $f$, the current leads the voltage by a phase angle of $45^{\circ}$. What is the value of $C$?

$A$ resistor of resistance $30 \Omega$, an inductor of reactance $10 \Omega$, and a capacitor of reactance $10 \Omega$ are connected in series to an $AC$ voltage source $V = 300 \sqrt{2} \sin(\omega t)$. The current in the circuit is . . . . . . (in $\text{ A}$)