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Parallel RLC circuit

The voltage source tex2html_wrap_inline456 .
  1. Find the complex number representation of the currents in R,L,C respectively.

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    displaymath431

    displaymath432

    displaymath433

  2. Show that the complex number representation of the total current delivered by the voltage source is:

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    displaymath435

    SOLUTION:

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    displaymath437

    where tex2html_wrap_inline460

  3. The inductor and capacitor resonate when tex2html_wrap_inline462 . Show that the total current at resonance is: tex2html_wrap_inline464 independent of L & C. So at resonance does any current flow in LC? Explain. (Derive expressions for the actual currents in R, LC).

    SOLUTION:

    At resonance tex2html_wrap_inline480 , so tex2html_wrap_inline482 .

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    From above:

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    (Note that tex2html_wrap_inline484 ).

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    displaymath442

    tex2html_wrap_inline486 at resonance so tex2html_wrap_inline488 and tex2html_wrap_inline490 have the same amplitude but differ tex2html_wrap_inline492 or tex2html_wrap_inline494 radians in phase. They add to zero.



Keith Jones
Fri Mar 3 10:00:43 EST 2000