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Homework Help: Electric bell description help

  1. Aug 22, 2012 #1
    describe how an electric bell operates (HINT: the make break contact dose not move; the hammer, however, moves bath and forth very quickly as it rings the bell)

    my solution

    An electric bell is a mechanical bell that functions by means of an electromagnet. When an electric current is applied, it produces a repetitive buzzing or clanging sound.

    more in depth
    When current is applied to the electromagnet part of the bell, it creates a magnetic pull on a metal lever-arm. The lever arm is attached to a clapper, which is pulled into strike the bell. The bell rings when it is hit.

    At the same time, the lever is attached to an electrical switch which opens up, which causes the current to stop in the electromagnet, which causes the magnetic pull to stop.

    A spring is also attached to the lever arm and when the magnet stops pulling, the spring (which is slightly weaker than the magnetic pull) pulls back on the lever arm. When this happens the switch closes and the electromagnet energizes again, and the process repeats over and over... ding, ding, ding, ding.

    is this worth 4 marks to you?
  2. jcsd
  3. Aug 22, 2012 #2


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    Staff: Mentor

    Looks good to me. https://www.physicsforums.com/images/icons/icon14.gif [Broken]
    Last edited by a moderator: May 6, 2017
  4. Aug 22, 2012 #3
    Last edited by a moderator: May 6, 2017
  5. Aug 22, 2012 #4
    could you help me with this!!

    which two of the three types of field discussed in this lesson were most similar> provide supporting evidence.

    there are electric, gravitational and magnetic..

    im guessing its electric and magnetic
    Last edited by a moderator: May 6, 2017
  6. Aug 23, 2012 #5


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    Staff: Mentor

    You have to come up with supporting evidence. Guessing doesn't work. Make a list of similarities/differences and see what you have.
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