A series LCR circuit is operated at resonance. Then

$$\begin{gathered} \mathrm{Impedence} \mathrm{is} \mathrm{minimum} \mathrm{at} \mathrm{resonance} {\mathrm{X}}_{\mathrm{L}}={\mathrm{X}}_{\mathrm{C}} \\ \mathrm{so}, \mathrm{Z}=\mathrm{R} \\ \mathrm{at} \mathrm{resonance}, {\mathrm{Z}}_{\min }=\mathrm{R} \\ \mathrm{so}, \mathrm{current} \mathrm{value} \mathrm{is} \mathrm{high} \mathrm{resonance}. \\ \mathrm{Power} \mathrm{transferred} \mathrm{is} \mathrm{maximum} \mathrm{as} \mathrm{value} \mathrm{of} {\mathrm{Z}}_{\mathrm{minimum}} \mathrm{at} \mathrm{resonance}. \\ \mathrm{Then} \mathrm{the} \mathrm{value} \mathrm{of} \mathrm{current} \mathrm{is} \mathrm{increase}. \mathrm{Hence} \mathrm{power} \mathrm{transferred} \mathrm{is} \mathrm{maximum}. \end{gathered}$$