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Q & A: Magnetic and electric lines of force

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Most recent answer: 07/10/2014
Why magnetic lines of force are closed but electrostatic are not?
- varun khare (age 16)

Hello Varun,

For the magnetic case there is no such thing as a magnetic monopole.  Magnetic fields arise from dipoles, such as a loop of a current carrying wire.  Many experiments have searched for magnetic monopoles but as yet none have been observed. As a consequence the divergence of the magnetic field  is zero and the magnetic field lines are closed.   

In the case of electric fields, electric monopoles do exist such as an electron or a positron.  In this case the divergence of the field is not zero and the field lines extend to infinity.  However you can devise systems of charge that will exhibit closed line solutions similar to those of a magnet.  You simply have a configuration consisting of a positive and a equal negative charge separated by a small distance.  The electric fields are closed, similar to those in a magnetic dipole.



(published on 07/10/2014)

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