The impedances of an AC bridge having an excitation voltage of 1kHz are as follows:: Arm AB with impedance Z = 1000 < 60 (inductive impedance) Arm AD with impedance Z = 3000 < 0 (purely resistive) Arm BC with impedance Z3 = 500 < 300 (inductive impedance) And arm DC with impedance Z =unknown impedance Determine the R, L or C components of the unknown impedance considering it as a series circuit.