Electrospun nanocomposite fibers were produced using polyvinylpyrrolidone (PVP), polyacrylonitrile (PAN), multiwall carbon nanotubes (MWCNTs), and Ni0.6Zn0.4Fe2O4 (NiZn ferrites) nanoparticles, and their physical properties, such as electrical, dielectrical, thermal, acoustic, and magnetic were determined. In this dissertation, various system parameters (e.g., polymers, solvents, and viscosity) and process parameters (e.g., electrical potential, pump speed, concentration, and distance) of the electrospinning process were studied in order to obtain the optimum properties of the nanocomposite fibers. MWCNTs are conductors, and NiZn-ferrite nanoparticles are semi-conductor materials; therefore, they alter the physical properties of electrospun fibers in a different way. A comparison was made between MWCNT-based fibers and NiZn ferrite-based fibers in terms of physical properties. As far as magnetic properties are concerned, only NiZn ferrite-based fibers have been used because MWCNT-based fibers do not exhibit magnetic properties. This dissertation determined to what extent the physical properties change when nanoscale inclusions are encapsulated in nanocomposite fibers. This study may open up new possibilities of using these products in various industrial applications (e.g., filtration and separation, high frequency antennas, magnetic storage, environmental sensors, biosensors, etc.) in the near future.