We present a new inductance measurement technique using a multi-frequency LCR meter. The inductance of superconducting (YBCO) delay lines was measured both as a function of temperature and bias current. The measured temperature dependence of the change in inductance for both meander and straight lines shows a square dependence on temperature, in good agreement with an unconventional pairing state. The effective magnetic penetration depth can be determined from the theoretical expression of the inductance for the case of a microstrip configuration with two identical superconducting films. The current-controlled inductance is well described by a modified Ginzburg - Landau equation.