that is, 1. To use moving electrically charge particle of a current in a wire, to make an electromagnet. 2. By means of elementary particles such as electrons because these particles have an intrinsic magnetic field around them. This is cause why some material can behave as a permanent magnet and some material cannot. Furthermore, the magnetic field exerts a force Fon any other moving charge or current that is present in
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Magnetic Field
the field. The direction of the magnetic field Bis defined as that in which the north pole of a compass needle tends to point. We can define a magnetic field Bat some point in space in terms of the magnetic force exerted on an appropriate test object. On test object is a charged particle moving with a velocity v, and for the time being we assume that there are no electric or gravitational fields present in
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Magnetic Field
the region of the charge. The magnitude of the magnetic force Fis proportional to the charge qand speed vof the particle. The magnitude and direction of the magnetic force depend on the velocity of the particle vand on the magnitude and direction of the magnetic field B. We find by experiment that the magnetic force F does not have the same direction as the magnetic field Bbut instead is always perpendicular to both B