Nickel zinc ferrite materials have significant bulk resistivities on the order of 10 to the 8th power ohms, while manganese zinc ferrites have very low resistivities. For power and inductive applications where a current-carrying conductor is wound directly on the ferrite core, it is important to take bulk resistivity into consideration. Under certain conditions, a worn enameled magnet wire could short to the ferrite. If using a manganese zinc core, it is advisable to use a part coated with a thermoset plastic or parylene-c coating.