The critical state of a superconducting ring caused by a current

c The distribution of a transport current in the branches of a superconducting ring of microwire at achievement of a critical state in one of branch microwire is experimentally investigated. This branch had a "weak" region in the form of local microwire narrowing or in the form of the point contact between microwires. Self-oscillations of a current in a ring with narrowing and their absence in a ring with the point contact are found out. The currents in the branches of a ring with the point contact change in steps when the direct transport current through the point contact exceeds critical value. The role of parametrical inductance of the "weak" region and the microstructure of point contact as quantum interferometer in the formation of critical state of the "weak" regions and features of the distribution of a current in the branches of the rings are discussed.