International Journal of Modern Physics and Application 2016; 3(1): 6-13 Published online January 6, 2016 (http://www.aascit.org/journal/ijmpa) ISSN: 2375-3870 Keywords Exact Solutions, Quark Stars: Anisotropic Matter Distribution, MIT–Bag Model, Tolman IV Potential, Einstein-Maxwell System Received: November 21, 2015 Revised: December 14, 2015 Accepted: December 16, 2015 New Models for Charged Anisotropic Stars with Modified Tolman IV Spacetime Manuel Malaver Maritime University of the Caribbean, Department of Basic Sciences, Catia la Mar, Venezuela Email address mmf.umc@gmail.com Citation Manuel Malaver. New Models for Charged Anisotropic Stars with Modified Tolman IV Spacetime. International Journal of Modern Physics and Application. Vol. 3, No. 1, 2016, pp. 6-13. Abstract In this paper, we found new exact solutions to the Einstein-Maxwell system of equations for quark stars within the framework of MIT-Bag Model considering modified Tolman IV type potential for the gravitational potential Z which depends on an adjustable parameter n and a particular form for the electric field intensity. The anisotropic matter distribution satisfies a linear equation of state consistent with quark matter. The exact solutions can be written in terms of elementary and polynomial functions in presence of an electromagnetic field. All the obtained solutions have a singularity in the charge density but do not admit singularities in the matter and metric functions. We show as a variation of the adjustable parameter causes a modification in the charge density, the electric field intensity, the radial pressure, the tangential pressure, the metric functions and the mass of the stellar object. A graphical analysis indicates that the obtained models satisfy all physical features expected in a realistic star. 1. Introduction From the development of Einstein´s theory of general relativity, the modelling of superdense mater configurations is an interesting research area [1,2]. In the last decades, such models allow explain the behavior of massive objects as neutron stars, quasars, pulsars, black holes and white dwarfs [3,4,5]. Malaver [3] studied the behavior of the thermal capacity C v for Schwarzschild´s black hole when T>>T C and T<<T C where T C is the characteristic temperature of the Schwarzschild black hole and found that the value for C v if T>>T C is the same that would be obtained in an ideal diatomic gas if only are considered the degrees of freedom rotational. Komathiraj and Maharaj [4] find new classes exact solutions to the Einstein-Maxwell system of equations for a charged sphere with a particular choice of the electric field intensity and one of the gravitational potentials. Sharma et al. [5] have obtained a class of solutions to the Einstein-Maxwell system assuming a particular form for the hypersurface (t=constant) containing a parameter λ. In theoretical works of realistic stellar models, is important include the pressure anisotropy [6-8]. Bowers and Liang [6] extensively discuss the effect of pressure anisotropy in general relativity. The existence of anisotropy within a star can be explained by the presence of a solid core, phase transitions, a type III super fluid, a pion condensation [9] or another physical phenomena as the presence of an electrical field [10]. The physics of ultrahigh densities is not well understood and many of the strange stars studies have been performed within the framework of the MIT-Bag model [11]. In this model, the strange matter equation of state has a simple linear form given by and B is the bag constant. Many researchers have used a great variety of mathematical