A simple circuit comprises a capacitor C shunted by a resistor R. Show that the frequency response of the circuit impedance, plotted in the complex plane, is represented by a semicircle of diameter R and with center at
Two such circuits are connected in series. In one the resistor and capacitor values are respectively 3 kΩ and 3.3 nF and in the other 10 kΩ and 1 µF. Sketch the expected frequency response of the impedance in the complex plane, marking the main features of the curves with numerical values.