The dielectric characterization of a liquid crystal by means of measurements of electric current. owing in the circuit is discussed. Few equivalent circuits are analyzed focusing the attention on the role of the resistance over which the potential drop is measured to determine the total current in the circuit. A comparison of our model with experimental data is presented, showing that the model works well when the maximum applied voltage is below the threshold voltage for Freedericksz's transition. In this case, the description of the nematic cell using a Maxwell-Wagner model is possible. (c) 2008 Elsevier B. V. All rights reserved.