An equipotential plane is a two-dimensional surface in which all points have the same electric potential. This means that no work is required to move a charge between any two points on the plane, since the potential difference is zero.
Equipotential planes are perpendicular to electric field lines. This means that the electric field at any point on the plane is always parallel to the plane itself. Electric field lines are also always perpendicular to equipotential lines.
No, equipotential planes cannot exist in isolation. They always exist in relation to electric fields, and are a result of the distribution of charges and the strength of the electric field in a given space.
Equipotential planes and electric fields are used in a variety of practical applications, such as in the design of electronic circuits, particle accelerators, and lightning rods. They are also used in determining the strength and direction of electric fields in various situations.
Charges will always move from higher potential to lower potential. Since equipotential planes have the same potential at all points, charges will not move if they are located on the plane. However, charges will move along the surface of an equipotential plane, as long as the potential remains constant.