Notices
Results 1 to 3 of 3
Like Tree2Likes
  • 2 Post By Physicist

Thread: Can magnetic field exist without electric field?

  1. #1 Can magnetic field exist without electric field? 
    Junior Member
    Join Date
    Aug 2014
    Location
    Lucknow, Uttar Pradesh, India
    Posts
    2
    Recently I bought - Introducing Relativity A Graphic Guide, in the book, after introducing Maxwell's theory of electromagnetism a line is written, "Simple magnetic fields can occur when there is no electric field (and vice versa)".
    I understand that electric field can exist without any magnetic field, although it is also generated by varying magnetic field, but as much I know, magnetic fields don't exist independently, they are generated by varying electric field or moving charge. Even in any magnetic substance, magnetic field is generated due to electrons orbiting the nucleus, and electrons have their own electric field, so electric field is present their too.
    How is it possible that magnetic field exists without any presence of electric field?
    Reply With Quote  
     

  2. #2  
    Senior Member
    Join Date
    Jun 2014
    Posts
    551
    Quote Originally Posted by amitSingh95
    How is it possible that magnetic field exists without any presence of electric field?
    Because even though there are electric fields they cancel each other out and all that remains is a magnetic field. Think about being in your living room with matter all around you. There are huge numbers of protons and the same number of electrons in that room. The electric field from the protons cancel the electric field of the electrons so that the net electric field is zero. That's how current in a wire works. There is a lattice of negative ions with electrons moving through it. The moving electrons create the magnetic field and the ions cancel out the electric field of the electrons.
    Jilan and amitSingh95 like this.
    Reply With Quote  
     

  3. #3  
    Banned
    Join Date
    Feb 2014
    Posts
    376
    How is it possible that magnetic field exists without any presence of electric field?
    Quote Originally Posted by Physicist View Post
    Because even though there are electric fields they cancel each other out and all that remains is a magnetic field. Think about being in your living room with matter all around you. There are huge numbers of protons and the same number of electrons in that room. The electric field from the protons cancel the electric field of the electrons so that the net electric field is zero. That's how current in a wire works. There is a lattice of negative ions with electrons moving through it. The moving electrons create the magnetic field and the ions cancel out the electric field of the electrons.
    It is a question of definition. The electric fields are there but they 'cancel out' as Physicist says - though on an atomic, not a macroscopic scale as would be found if your magnetic field was actually the result of a current-carrying electric wire.

    IOW the electric fields are not present everywhere the magnetic field is, hence LOCALLY one may detect the magnetic field's presence without detecting the electric field, such electric field being found within a bar magnet for example, but not outside of it.

    TFOLZO
    Reply With Quote  
     

Tags for this Thread

View Tag Cloud

Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •