RC response problem


Joined 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.
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Thread Starter


Joined 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?