Loop crossing a magnetic field boundary
= Loop crossing a magnetic field boundary
A square resistive loop of side $a$, moving normally across a sharp field edge at <speed> $v$, has induced current magnitude $Bav/R$ and drag magnitude $B^2a^2v/R$ while partially overlapping the field. Completely enclosed in a uniform static field it has no changing flux and, with neglected <self-inductance>, no current.