Earth has a magnetic dipole moment of 8.0 ⋅ 10 22 J / T.(a) What current would have to be produced in a single turn of wire extending around Earth at its geomagnetic equator if we wished to set up such a dipole? Could such an arrangement be used to cancel out Earth’s magnetism (b) at points in space wellabove Earth’s surface or (c) on Earth’s surface?

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Earth has a magnetic dipole moment of   8.0  ⋅      10          22           J      /    T.(a) What current would have to be produced in a single turn of wire extending around Earth at its geomagnetic equator if we wished to set up such a dipole? Could such an arrangement be used to cancel out Earth’s magnetism (b) at points in space wellabove Earth’s surface or (c) on Earth’s surface?

Kole Weber · Accepted Answer

a) Current have to be produced in a single turn of wire extending around Earth at its geometric equator if we wished to set up such a dipoleThe expression for the magnetic moment is  μ  =  N  I  A    I  =      μ          N      A          =      μ          N      (      π              r        2            )      Substitute all the values to find the current  I  =            8.0      ×              10                  22                           J              /            T              1      T      (      π      (      6.378      ×              10        6                    )        2            )          =  6.3  ×      10    8       Ab) Yes, because far away from the Earth surface, both magnetic dipole moments are same. If they are equal and opposite, then the net field will be zero.c) No, because the magnetic fields of both are not the same. Thus, both the fields will not cancelling out each other.

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