What is a magnetism ?what is a magnetic flux? what is difference b/w electric flux and magnetic flux ?

Magnetism: a physical phenomenon produced by the motion of electric charge, which results in attractive and repulsive forces between objects.

Magnetic flux (most often denoted as Φm), is the number of magnetic field lines (also called "magnetic flux density") passing through a closed surface (such as a conducting coil). The SI unit of magnetic flux is the weber (Wb) (in derived units: volt-seconds). The CGS unit is the maxwell.


Magnetic flux exists and is defined by Maxwell's equations. A popular misconception is that "lines of force" exist. While they often simplify calculations, and make it easier to envision magnetic flux, they sometimes give a disastrously wrong answer. Their use should be avoided.

An example is a rotating metal disc glued on the end of a bar magnet. Maxwell's equations will correctly predict the voltage generated (vxB), "lines of force" incorrectly predict that no voltage is generated. Even some professional engineers believe that no voltage is generated if the magnet rotates with the disc, and have been known to try the experiment themselves to be sure