RC time constant...

Discussion in 'General Electronics Chat' started by i3ill, Dec 7, 2008.

  1. i3ill

    Thread Starter New Member

    Dec 7, 2008
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    Doing some homework for my basic DC electronics class and do not know how to answer this question!
    The RC time constant of a circuit consisting of a 10k resistor in series with a 50 uF capacitor is _______. When a power supply is connected to this RC circuit, it is generally considered that the capacitor will be fully charged in ________ time constants, which would be ________ seconds.

    Help Help!
     
  2. hgmjr

    Moderator

    Jan 28, 2005
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    What answers have you been able to calculate on your own?

    hgmjr
     
  3. Wendy

    Moderator

    Mar 24, 2008
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    Concerning the 1st problem, this is one of those rare situations the description is also the equation.
     
  4. thingmaker3

    Retired Moderator

    May 16, 2005
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  5. Wendy

    Moderator

    Mar 24, 2008
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    I just reviewed the chapter, it doesn't give the answer for the 2nd question. I remember the answer from my school days. Till the OP gets the first problem I'm not too worried about it though.
     
  6. TanTJ

    Member

    Mar 6, 2008
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    I'm pretty sure I know the answer as well, but don't want to give it away. Is the answer to the second part of the question the derivative of the function f(x)=5x+7? If you get my meaning :)
     
  7. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    Isn't the second part like similar questions related to any rate equation? That is, what do you consider fully charged, reacted, or whatever: 86%, 95%, 99%, etc? The answer will be what the instructor told you. The exponent is usually 3, 4, or 5 for practical purposes. I tend to prefer 4 or even 3, if the time constant is long; although, some people stick rididly to 5 (99%).

    John
     
  8. Wendy

    Moderator

    Mar 24, 2008
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    That's what I was taught... :p
     
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