The resonant frequency of an $L-C$ circuit is

In a series $R-L-C$ circuit,the frequency of the source is half of the resonance frequency. The nature of the circuit will be

In an $LC$ parallel resonance circuit,choose the wrong statement.

An a.c. e.m.f. of peak value $V_0 = 230 \ V$ and frequency $f = 50 \ Hz$ is connected to a circuit with $R = 11.5 \ \Omega$,$L = 2.5 \ H$ and a capacitor $C$ all in series. For the current in the circuit to be maximum,the circuit must be in resonance. Find the value of $C$ and the maximum current $I_{max}$ (take $\pi^2 = 10$).

$A$ resonance circuit having inductance and resistance $2 \times 10^{-4} \ H$ and $6.28 \ \Omega$ respectively oscillates at $10 \ MHz$ frequency. The value of the quality factor of this resonator is .........
$[\pi = 3.14]$

In the given $LCR$ circuit,the voltage across the terminals of the resistance and the current in the circuit will be: