Microwave cavity spectrometer has been used to measure the width of resonant profile and the shift of the resonant frequency. The observed data are analyzed to determine permittivity, dielectric loss and relaxation time. The relative variation of dielectric loss and permittivity at different temperatures has been studied for the purpose to monitor the phase changes in the range 282 degrees K to 314 degrees K and to identify the transition temperatures. We have used two frequencies 9.0 GHz and 29.867 GHz to see the frequency dependence for the purpose to compare relaxation mechanism. The technique used is useful as it needs if small quantity (< 0.001 cm(3)) of the sample and provides fruitful information about the macroscopic structure of the liquid crystal. The transition temperatures are TC -->N = 287.6 degrees K and TN -->I = 301.9 degrees K.