Module 1: Magnets and magnetism

XSIQ
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Physics - Forces on current-carrying wires

Forces on current-carrying wires

Analogous to the previous situation, instead of freely-moving charges
passing through a field, the charges may be part of a conducting wire. The
same principle applies. While the current is flowing, the field will exert
a force on the wire. The right-hand slap rule again describes the direction
of this force. The thumb must be aligned with the direction of conventional
current, and the fingers with the magnetic field lines. The palm then
indicates the direction of the force on the wire. A wire would physically
be made to move. This force occurs because the magnetic field produced by
the current in the wires interferes with the external magnetic field. The
size of the force exerted on the conducting wire is given by:

For the conducting wire to experience maximum force, the wire must be
placed perpendicular to the field lines. If the wire is placed on an angle
then the force is reduced, as effectively only the component of the wire
that is perpendicular to the field contributes to the equation above.

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