In a series RLC high Q circuit, the current peaks at a frequency

The resonant frequency of this series circuit shown in figure is

The transfer function of simple RC network functioning as a controller is $$$G\,{}_c\left( s \right)\,\,\,\,{{s + {z_1}} \over {s + {p_1}}}$$$

The condition for the RC network to act as a phase lead controller is

The half - power bandwidth of the resonant circuit of figure can be increased by