In an $L-C-R$ series circuit, the value of only capacitance $C$ is varied. The resulting variation of resonance frequency $f_0$ as a function of $C$ can be represented as

The figure shows variation of $R, X_L$ and $X_C$ with frequency $f$ in a series $L-C-R$ circuit. Then, for what frequency point is the circuit capacitive?

Total impedance of a series $$L$$-$$C$$-$$R$$ circuit varies with angular frequency of the $$\mathrm{AC}$$ source connected to it as shown in the graph. The quality factor $$Q$$ of the series $$L$$-$$C$$-$$R$$ circuit is

In series $$L C R$$ circuit at resonance, the phase difference between voltage and current is