Hey there! Sign in to join this conversationNew here? Join for free
    • Thread Starter
    Offline

    0
    ReputationRep:
    I have a discharging capacitor connected to 2 power rails (6V and 0V) The capacitor has a value of 100 micro farads and the resistor in parallel with is has a value of 1.3 mega ohms (so a time constant of 130 seconds.) The question is calculate the time at which Vout=3v (assuming discharging begins at time=0)
    I got an answer of 90.1 but I'm not sure if its correct? I'm kinda going from memory for the equations you see thanks in advance
    Offline

    9
    (Original post by afc4l)
    I have a discharging capacitor connected to 2 power rails (6V and 0V) The capacitor has a value of 100 micro farads and the resistor in parallel with is has a value of 1.3 mega ohms (so a time constant of 130 seconds.) The question is calculate the time at which Vout=3v (assuming discharging begins at time=0)
    I got an answer of 90.1 but I'm not sure if its correct? I'm kinda going from memory for the equations you see thanks in advance
    That's the correct answer.
    t1/2 = CR Ln 2
    Obtained from exponential decay formula after taking logs.
 
 
 
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • Poll
    Would you like to hibernate through the winter months?
  • See more of what you like on The Student Room

    You can personalise what you see on TSR. Tell us a little about yourself to get started.

  • The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

    Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

    Quick reply
    Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.