A circuit when connected to an AC source of 12 V gives a current of 0.2 A. The same circuit when connected to a DC source of 12 V, gives a current of 0.4 A. The circuit is

11=vZ I1=12R2+XL-XC2=0.2AIn second case for DC source, capacitor would provide infinite resistance but current is present in circuit, it means resistor and inductor can be present in the circuit. As the current with AC source and DC source are different, inductor must be present with resistance.