Magnetic Fields & Electromagnetic Induction

Force on a current-carrying conductor

A current in a magnetic field experiences a force:

$$F = BIL\sin\theta$$

where $B$ is the magnetic flux density (tesla, T), $I$ the current, $L$ the length in the field and $\theta$ the angle between the current and the field. The force is maximum when the current is perpendicular to the field ($\theta = 90^\circ$) and zero when parallel. Fleming's left-hand rule gives the direction (thumb = force/motion, first finger = field, second finger = current).