This magnetic field diagram depicts the imaginary lines used to represent magnetic fields. Magnetic field lines show the direction and strength of the magnetic force. Magnetic field lines extend from the magnet's north pole to the magnet's south pole. The magnetic field lines covering a bar magnet are depicted in the magnetic field diagram figure below. Magnetic field lines are fictitious lines that define magnetic fields. It indicates the magnetic force's direction. The use of magnetic field lines as a representation has the advantage of allowing laws of magnetism and (electromagnetism) to be stated using concepts such as the 'number' of field lines through a surface. Magnetic field lines, like streamlines in fluid flow, represent something continuous that could have a different resolution.
