The thermal dependence of optical and dielectric properties of one member namely 4-(4-propylcyclohexyl)phenyl 4-butylcyclohexanecarboxylate (HD34) of the mesogenic homologous series 4-(4-propylcyclohexyl)phenyl 4-alkylcyclohexanecarboxylate is reported. In particular, the thermal variation of orientational order parameter and the effect of temperature on the effective molecular dipole moment and the angle of inclination of the dipole axis with the prefered direction are investigated. The experimental order parameter values have been compared with theoretical Maier-Saupe values. Comparison of these electro-optical properties have been made with those of the next higher member (HD35) of the series to study the effect of increasing chain length.