  We investigate theoretically the magnetization loss and electromagnetic
coupling of twisted multi-filament superconducting (SC) tapes in a ramped
magnetic field. Based on the two-dimensional reduced Faraday--Maxwell equation
for a tape surface obtained with a thin-sheet approximation, we simulate
numerically the power loss $P$ per unit length on twisted multi-filament tapes
in the steady state. The current density profile clearly shows electromagnetic
coupling between the SC filaments upon increasing the field sweep rate $\beta$.
Although the $\beta$ dependence of $P/\beta$ for twisted multi-filament SC
tapes closely resembles that for filaments in an alternating field, we show
that the mechanism for electromagnetic coupling in a ramped field differs from
that in an alternating field. We also identify the conditions under which
electromagnetic coupling is suppressed for the typical sweep rate of a magnet
used for magnetic resonance imaging.
