2nd year of post-compulsory secondary education
Magnetic field
José Luis San Emeterio
 Magn.  
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The effects of the magnetic field on a straight cable
   If the magnetic field affects charged particles in movement, then it must also affect a conductor through which a current is flowing. The charged particles moving through it will be pushed in some direction by the field. As they are confined inside the conductor, they will exert a measurable force on it.
   In the visual , you can observe the effect of the magnetic field on a straight cable. If the conductor is curved, or if the field is not homogeneous, then it is necessary to imagine the conductor is composed of an infinite number of small straight fragments of length dL and add up (integrate) the forces acting on each and every one of them. 

   The direction of the force is given by the left hand rule: if the index finger points in the direction of the field and the middle finger in the direction of the current, then the thumb will point in the direction of the force.

Background information
Natural magnets
Lines of force
Magnets and currents
Conclusions
The effects of the magnetic field
on a charged particle
on a straight cable
on a loop
Conclusions
The creation of magnetic fields
by a charged particle
by a rectilinear current
by a coil
An explanation of natural magnetism
Conclusions
Induced currents
Magnetic flux
The laws of Faraday and Lenz
Self-induction
Conclusions
Alternating current
The generation of alternating currents
A circuit of alternating current
Conclusions
Evaluation