Power dissipated in an $LCR$ series circuit connected to an $a.c.$ source of electromotive force (emf) $\varepsilon$ is:

Given below are the two circuits, choose the correct option.

In an $LCR$ circuit,$R = 100 \ \Omega$. When the capacitor $C$ is removed,the current lags behind the voltage by a phase of $\pi / 3$. When the inductor $L$ is removed,the current leads the voltage by a phase of $\pi / 3$. What is the impedance of the circuit in $\Omega$?

An inductor of $10 \text{ mH}$, capacitor of $0.1 \text{ } \mu\text{F}$ and a resistor of $100 \text{ } \Omega$ are connected in series across an $a.c.$ power supply of $220 \text{ V}$, $70 \text{ Hz}$. The power factor of the given circuit is $0.5$. The difference between the inductive reactance and capacitive reactance is $\sqrt{3}\alpha \text{ } \Omega$. The value of $\alpha$ is . . . . . . .

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

An $LCR$ series circuit with $R = 100\,\Omega$ is connected to a $200\,V, 50\,Hz$ $a.c.$ source. When only the capacitance is removed,the current lags the voltage by $60^o$. When only the inductance is removed,the current leads the voltage by $60^o$. The current in the circuit is.....$A$