What is the reason we prefer $A.C.$ voltage over $D.C.$ voltage for power transmission?

Give the name of the physical quantity in an $LCR$ circuit that corresponds to displacement $x$ in forced oscillations.

$A$ resistor $R=300 \Omega$ and a capacitor $C=25 \mu F$ are connected in series with a $50 \ V, \frac{50}{\pi} \ Hz$ $AC$ source. The average power dissipated in the circuit is (in $W$)

$L$,$C$,and $R$ denote inductance,capacitance,and resistance respectively. Pick out the combination which does not have the dimensions of frequency.

Assertion : In the purely resistive element of a series $LCR$ $AC$ circuit,the maximum value of $rms$ current increases with an increase in the angular frequency of the applied $e.m.f$.
Reason : $I_{\max} = \frac{\varepsilon_{\max}}{Z}$,where $Z = \sqrt{R^2 + (\omega L - \frac{1}{\omega C})^2}$ and $I_{\max}$ is the peak current in a cycle.

An inductor stores $16 \ J$ of magnetic field energy and dissipates $32 \ W$ of thermal energy due to its resistance when an $A.C.$ current of $2 \ A$ $(rms)$ and frequency $50 \ Hz$ flows through it. The ratio of inductive reactance to its resistance is . . . . . . . $(\pi=3.14)$