  We study the N/Z dependence of balance energy (E$_{bal}$) for isotopic series
of Ca having N/Z varying from 1.0 to 2.0. We show that the N/Z dependence of
E$_{bal}$ is sensitive to symmetry energy and its density dependence at
densities higher than saturation density and is insensitive towards the isospin
dependence of nucleon-nucleon cross section
