When a conductor cuts a magnetic induction line, the current generated is related to the size (cross section) of the conductor. The larger the cross section of the conductor, the greater the induced current.

Assuming that the magnetic induction line is cut by the iron plate and does not form a loop, then there is only eddy current inside the iron plate. Whether it is edge cutting or surface cutting, the size of eddy current is related to the area and thickness of iron plate, and the thick or large eddy current is large.

The magnetic induction wire is cut from the iron plate, and the loop formed by the iron plate and the conductor is related to the area and thickness of the iron plate. In this case, eddy currents also exist in the iron plate.

The actual situation is complicated, and the above description is rough and simple qualitative description.