Alternating Current

For a given series LCR circuit it is found that maximum current is drawn when value of variable capacitance is \(2.5 \mathrm{~nF}\). If resistance of \(200 \Omega\) and \(100 \mathrm{~mH}\) inductor is being used in the given circuit. The frequency of ac source is _________ \(\times 10^3 \mathrm{~Hz}\) (given \(\mathrm{a}^2=10\))