Magnetic Force Acting on a Current-Carrying Conductor. (a) Magnetic field lines coming out of the paper are indicated by dots, representing the tips of arrows coming outward. (b) Magnetic field lines going into the paper are indicated by crosses, representing the feathers of arrows going inward.
(a) Magnetic field lines coming out of the paper are indicated by dots, representing the tips of arrows coming outward.
A segment of a current-carrying wire in a magnetic field B. The magnetic force exerted on each charge making up the current is q vd x B and the net force on the segment of length L is I L x B.
(a) A wire suspended vertically between the poles of a magnet. (b) The setup shown in part (a) as seen looking at the south pole of the magnet, so that the magnetic field (blue crosses) is directed into the page. When there is no current in the wire, it remains vertical. (c) When the current is upward, the wire deflects to the left. (d) When the current is downward, the wire deflects to the right
The magnetic force exerted on a small segment of vector length ds in the presence of a field B is
A wire segment of
arbitrary shape carrying a current I
in a magnetic field B experiences a
magnetic force. The magnetic
force on any segment ds is I ds x B
and is directed out of the page. You
should use the right-hand rule to
confirm this force direction.
(a) A curved wire carrying a current I in a uniform magnetic field. The total magnetic force acting on the wire is equivalent to the force on a straight wire of length L( running between the ends of the curved wire. (b) A current-carrying loop of arbitrary shape in a uniform magnetic field. The net magnetic force on the loop is zero.
These results show that the angular speed of the particle and the period of the circular motion do not depend on the linear speed of the particle or on the radius of the orbit.
If a charged particle moves in a uniform magnetic field with its velocity at some arbitrary angle with respect to B, its path is a helix
The magnetic field
dB at a point due to the current I
through a length element ds is
given by the Biot–Savart law. The
direction of the field is out of the
page at P and into the page at P%
attract each other, and parallel conductors carrying currents in opposite directions
repel each other.
Ampère’s law describes the creation of magnetic fields by all continuous current configurations
(a) Magnetic field lines for a tightly wound solenoid of finite length,carrying a steady current. The field in the interior space is strong and nearly uniform.Note that the field lines resemble those of a bar magnet, meaning that the solenoideffectively has north and south poles.
Magnetic flux through a plane lying in a magnetic field.(a) The flux through the plane is zero when the magnetic field is parallel to the planesurface. (b) The flux through the plane is a maximum when the magnetic field is perpendicular to the plane.