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Building a solenoid

  1. Jul 16, 2014 #1
    Hello so I just want to make sure I Am doing this correctly. ImageUploadedByPhysics Forums1405535637.088417.jpg also I know there is a magnetic field force formula. That is F= qv (dot) B
    How would I go about using that formula with the magnetic field I created from the solenoid in the picture?

    Thanks for any help!
  2. jcsd
  3. Jul 16, 2014 #2


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    It's really hard to read the text in the picture. Can you summarize by posting it?
  4. Jul 16, 2014 #3
    Ok I'm using the equation B= unI

    Once I plug in the numbers I get n= 18/.504=35.7142, u= 2.513*10^-4.
    So if I have 10 amps then my final number should be .0897 B. Did I do that correct?
  5. Jul 17, 2014 #4


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    For the values you have assumed, the calculations seem correct. About the magnetic field force formula, you are referring to Lorentz force formula:##F=q (\vec{v}\times\vec{B})##
  6. Jul 17, 2014 #5
    Ok well what I don't understand about that equation is the velocity part. I have been trying to do some reading on it, but I don't understand it. Is the velocity for the speed of the electron or something else?
  7. Jul 17, 2014 #6


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  8. Jul 18, 2014 #7
    Ok I will try and get it then show my work to make sure I'm doing it correctly. Thank you for the help!! Zig
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