Bath excess height occurs in crucible induction furnaces as a result of the potential forces in the melt. According to the law of induction, a conductor with a current flowing through it is subject to a movement force, which in a crucible induction furnace acts vertically to the wall, and thus pushes the melt away from the crucible wall. The melt can only compensate for this force in an upward direction, and this creates the bath cone, which is higher or lower depending on the output and frequency.