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Homework Help: Electron current homework

  1. Mar 5, 2008 #1

    tony873004

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    A single electron in uniform circular motion constitutes an average current around the circle. If the electron moves clockwise with angular speed in a circle of radius r, find the current. Evaluate I if [tex]\omega=2X10^{16}[/tex] rad/s and r = 5 nm.

    I never used radius r in my answer. This book usually doesn't thrown in irrelavant information in the questions. Did I do this right?

    [tex]\begin{array}{l}
    I = \left| {\frac{Q}{t}} \right| \\
    \\
    t = \frac{d}{v} = \frac{{2\pi }}{\omega } \\
    \\
    I = \left| {\frac{Q}{{\left( {\frac{{2\pi }}{\omega }} \right)}}} \right| = \left| {\frac{{Q\omega }}{{2\pi }}} \right| = \left| {\frac{{ - e\omega }}{{2\pi }}} \right| = \frac{{e\omega }}{{2\pi }} \\
    \\
    \frac{{1.602 \times 10^{ - 19} {\rm{C}} \times 2 \times 10^{16} {\rm{rad/s}}}}{{2\pi }} = 5.1 \times 10^{ - 4} {\rm{C/s = }}5.1 \times 10^{ - 4} {\rm{A}} \\
    \end{array}[/tex]
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Mar 5, 2008 #2

    Shooting Star

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    Right. The current would be in the CCW direction. (I haven't checked the arithmetical calculation.)
     
  4. Mar 5, 2008 #3

    tony873004

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    Thanks for verifying that, and reminding me to include direction.
     
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