  We calculate the meniscus location in tapered capillaries under the influence
of pressure difference and dielectrophoretic forces with and without gravity.
We find that the meniscus location can be a discontinuous function of the
pressure difference or the applied voltage and that the meniscus can ``jump''
to one end or another of the capillary. Phase diagrams are given as a function
of the pressure and voltage, depending on the geometrical parameters of the
system. We further consider a revision of the dielectric rise under
dielectrophoretic force in wedge capillaries and in the case of electrowetting,
where the dielectrophoretic force is a small perturbation. Finally, we also
find discontinuous liquid--gas interface location in the case of liquid
penetration into closed volumes.
