The dielectric anisotropy and dispersion of the real and imaginary part of the permittivity of commercially important nematic mixture E-24 and its polymer composite were investigated in the frequency range from 1 kHz to 10 MHz, and temperature range $14^{circ}C$ to $55^{circ}C$. The percentage optical transmittance and density have also been measured for both the systems. The results have been explained by assuming molecular rotation about the long molecular axis, under a hindering nematic potential. The dielectric anisotropy ${Delta}{varepsilon}$ is positive, and the mean dielectric permittivity falls with rising temperature. ${Delta}{varepsilon}$ is also used to determine the order parameter with varying temperature.