jõujoon
Jõujoon is an Estonian term that translates to "force line" or "line of force." It is a concept primarily used in physics and engineering to visualize the direction and magnitude of forces. These lines are typically drawn to represent fields of force, such as magnetic fields or electric fields. The direction of the force line at any given point indicates the direction of the force acting on a test particle or charge at that location. The density of the force lines, meaning how close together they are, represents the strength of the force. Where the lines are closer, the force is stronger, and where they are farther apart, the force is weaker.
In the context of magnetic fields, jõujooned emerge from the north pole of a magnet and enter