  We perform a detailed physical analysis for a class of exact solutions for
the Einstein-Maxwell equations. The linear equation of state consistent with
quark stars has been incorporated in the model. The physical analysis of the
exact solutions is performed by considering the charged anisotropic stars for
the particular nonsingular exact model obtained by Maharaj, Sunzu and Ray. In
performing such an analysis we regain masses obtained by previous researchers
for isotropic and anisotropic matter. It is also indicated that other masses
and radii may be generated which are in acceptable ranges consistent with
observed values of stellar objects. A study of the mass-radius relation
indicates the effect of the electromagnetic field and anisotropy on the mass of
the relativistic star.
