very simple question, plz I need the answer

Discussion in 'General Electronics Chat' started by fankoushat, Mar 28, 2010.

  1. fankoushat

    Thread Starter New Member

    Mar 8, 2010
    17
    0
    Hi guys,

    Consider the following circuit:

    http://www.postimage.org/image.php?v=gxFeffA

    V source , connected in series with resistor R , and open circuit.

    what is the voltage dropped between the open circuit terminals?

    equal to V source, or equal to V source - V dropped on R?

    Thanks alot
     
    Last edited: Mar 28, 2010
  2. dsp_redux

    Active Member

    Apr 11, 2009
    182
    5
    I don't see any circuits...?
     
  3. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    There is no current in the circuit, so there is no drop across the resistor.
     
  4. dsp_redux

    Active Member

    Apr 11, 2009
    182
    5
    V=R*I
    If I=0A from the open circuit, V=0V. Same thing beenthere said.
     
  5. Jony130

    AAC Fanatic!

    Feb 17, 2009
    3,957
    1,097
    But voltage between the open circuit terminals is equal Vsource
     
  6. fankoushat

    Thread Starter New Member

    Mar 8, 2010
    17
    0
    thanks johny, but why people say " the inductor at the beginning of connecting it with a dc source, will have voltage difference equals to V source - V dropped on R, because it is considered as open circuit".

    So voltage difference measured between the two open circuit terminal will be the same as V source.
     
  7. dsp_redux

    Active Member

    Apr 11, 2009
    182
    5
    When you do a DC analysis, you can consider capacitors as "open circuit" and inductors as "short circuit". There is no voltage drop in a short circuit. DC voltage is considered as a "0 frequency" or 0Hz. Impedance of a capacitor is X_C = \frac{1}{2\pi f C}. If you take f\rightarrow 0, X_C=\infty hense the capacitor considered as an open circuit. For the inductor X_L = 2\pi f L. X_L = 0 when f=0. It is considered as a short circuit.
     
  8. redlight000

    Member

    Feb 26, 2010
    66
    2
    Hi dsp,
    Just asking how do you get those electronic equations on the post? are they built in this actual forum?? or you got a special program to do it??

    Why I ask I've got a few maths questions to ask..
    many thanks
    from
    redlight000
    :D
     
  9. SgtWookie

    Expert

    Jul 17, 2007
    22,182
    1,728
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