The basic element of a electrical system are (i) resistor, (ii) inductor and (iii) capacitor.
From Fig. 5.19, we can write
Fig. 5.19 Resistor
From Fig. 5.20, we get
Fig. 5.20 Inductor
where v is voltage and i is current.
From Fig. 5.21, we can write
Fig. 5.21 Capacitor
where v is voltage and i is current. ...