What are the imaginary lines called that are used to visualize a magnetic field?

The term for the imaginary lines that represent the direction and strength of a magnetic field is "magnetic field lines." These lines are a crucial tool in physics for visualizing how magnetic forces operate in space. They illustrate the paths along which a north magnetic pole would move if placed in the field.

Magnetic field lines are drawn such that they emanate from the north pole of a magnet and terminate at the south pole, showing the direction of the magnetic field. The density of these lines indicates the strength of the magnetic field: where the lines are closer together, the field is stronger. They also provide insight into the behavior of magnetic materials and the interaction between magnets.

The other terms, while they may seem relevant, either do not accurately describe this concept or are not standard terminology used in physics to describe the visualization of a magnetic field.