RC response problem

Discussion in 'General Electronics Chat' started by PG1995, Oct 28, 2011.

  1. PG1995

    Thread Starter Active Member

    Apr 15, 2011

    I'm trying to solve Practice Problem 7.10. But I'm stuck. I'm not even sure if my procedure is correct. Please help me with it. Many thanks.

  2. Jony130

    AAC Fanatic!

    Feb 17, 2009
    Why you use mesh analysis instead of Ohms law for such a simple circuit?

    The right voltage source is equal to 50V not 5V.

    And the current is simply equal to:
    I' = 10V/8Ω = 1.25A
    I'' = 50V/8Ω = 6.25A

    Itotal = I' + I'' = 1.25A + 6.25A = 7.5A

    Or as you should see from the diagram, that the two voltage source are connect in series.
    So we can write by inspection

    Itot = ( 10V + 50V) /8Ω= 7.5A

    So V(∞) = -5V

    And now you can start to find the time constants.
    Last edited: Oct 28, 2011
    PG1995 likes this.
  3. PG1995

    Thread Starter Active Member

    Apr 15, 2011
    Thank you, Jony.

    I realize it now. The hard copy of the book I have is 3rd edition while the e-book version is 4th ed. I think there was a mistake in 3rd edition which I was using. So, it's 50V, not 5V.

    By the way, how do we solve such problems on circuit simulators such as Multisim or Circuit Wizard?