Question

How the magnetic flux links to rod changes?

Answer 1

The magnetic field strength, B, multiplied by the area swept out by a conductor, A, is called the magnetic flux, φ.

φ = BA

Units of flux: weber, Wb.

You can think of flux as being the amount of magnetic field that you've swept through (not just the area you swept through, but area x field strength.)

The more magnetic flux you sweep through per second, the more emf you induce. Remember the area must be perpendicular to the field!