A rotor for a synchronous machine of a motor vehicle includes an excitation coil configured to generate a magnetic field necessary for rotation of the rotor in a stator of the synchronous machine. The rotor also includes a supply circuit, to which energy is fed contactlessly such that the supply circuit supplies the excitation coil with the energy. The rotor also includes a demagnetization circuit configured to demagnetize the excitation coil, which, upon collapse of the energy supply of the excitation coil, diverts a current flowing through the excitation coil into a circuit branch in which at least one component for demagnetization is arranged, wherein the at least one component is also configured to perform a protection function to protect the supply circuit against an induced voltage generated at the excitation coil.