Motor Effect

The motor effect is the force experienced by a current-carrying conductor placed in a magnetic field. When current flows through a wire inside a magnetic field, the magnetic field of the wire interacts with the external magnetic field. This interaction produces a force on the wire.

Use **Fleming's Left-Hand Rule**. Hold the thumb, first finger and second finger of the left hand mutually perpendicular. First finger → magnetic field. Second finger → current. Thumb → force or motion.

For a straight conductor: **F = BIL sin θ where: `F` = force `B` = magnetic flux density `I` = current `L` = length in field `θ` = angle between current and magnetic field Maximum force occurs at: θ = 90°**

Force increases when: magnetic field strength increases; current increases; * conductor length in the field increases.

Motor effect is used in: electric motors; loudspeakers; * moving-coil meters.