The core of the problem is "If the magnet is located in this position, what about the attraction of the electromagnet over the magnet?"What about the dipole-dipole interaction? If suitable, the overall magnetic moment could be given by m → = m c o i l → + m c o r e → , where m c o i l → = N i S → ( i = current, N = number of winding, | S → | = area of a single loop). Is it correct?If the dipole - dipole approximation is not suitable, what else?

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The core of the problem is &quot;If the magnet is located in this position, what about the attraction of the electromagnet over the magnet?&quot;What about the dipole-dipole interaction? If suitable, the overall magnetic moment could be given by             m      →        =                    m                  c          o          i          l                    →        +                    m                  c          o          r          e                    →      , where                     m                  c          o          i          l                    →        =  N  i            S      →       (  i = current,   N = number of winding,       |              S      →            |   = area of a single loop). Is it correct?If the dipole - dipole approximation is not suitable, what else?

Willow Avery · Accepted Answer

If you are interested in the static problem, you could use the following steps:1. Use Biot-Savart&#039;s law to calculate the magnetic field             B      →        (  x  ,  y  ,  z  ). Use a grid to obtain the field at different positions.2. The energy of the &quot;small&quot; magnet is given by   E  =  −            μ      →        ⋅            B      →      .3. Take the &quot;derivative&quot; (gradient) to obtain the force             F      →      .For certain configurations there are exact formulas. Hence, you should probably cross-check your numerics using these special configurations.

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