The monograph is devoted to the consideration of a fairly wide range of problems of electro-hydrodynamics and electrophysics. The main attention is paid to the problems of stability of the equilibrium of charged liquids in the electric field (flat surface, drop, jet), electroconvection, as well as some problems of atmospheric electricity (including the problem of ball lightning). In most solved problems, theoretical conclusions are compared with the experiment or the corresponding applied problems (boiling, cavitation, convection) are considered. Along with the presentation of known and classic results in the monograph, new results obtained by the author are presented. For specialists in the field of hydrodynamics, atmospheric electricity and related fields, university teachers, graduate students and senior students .