How to find Vab ?
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hi Ahmed,
Welcome to AAC,
As this is homework please post your attempt at answering, we can then help you.
E
This is what I got , I don't know if it's right or nothi Ahmed,
Welcome to AAC,
As this is homework please post your attempt at answering, we can then help you.
E
There's almost always going to be some round off error involved, so if the current is negligible, then that is okay. The thing that you have to be a bit careful of is what counts as "negligible". Just because it's small doesn't mean it's negligible. For instance, consider a circuit that has a Thevenin equivalent resistance of 10 MΩ and a Thevenin voltage of 10 V. If I screw up and come up with a Thevenin voltage of 110 V and plug it into my original circuit I would get a current flow in it of 10 uA, which I might be tempted to call negligible, but it certainly isn't. On the other hand, if I had a circuit that had a Thevenin equivalent resistance of 10 mΩ and the same 10 V Thevenin voltage and my answer turned out to be 10.1 V (i.e., within 1% of the correct value), then the current in the source would turn out to be 10 A and I might be tempted to declare my answer complete wrong. So "negligible" needs to be put into a meaningful context; the most useful one for a problem like this would probably be as a fraction of the short-circuit current.Well the current should be zero , but I got a small current , if why say that it's negligible , Vth might be right ,,
You can always brute for the analysis and be guaranteed to get the correct answer (barring mistakes), but with a bit of consideration you can often come up with significantly cleaner and quicker ways to get the correct answer for the specific problem at hand. In this case you know that the current from the left hand source must all flow through the left hand branch and the voltage that is produced is then added to the voltage of the right hand source because you know that there is no current flowing in that 4 Ω resistor when the terminals are open.I saw the prof's answer it is definitely not like mine lol , he just added the source connected to a terminal with the source in the first branch lol ,,, when I first saw it , I was like WOT IS THAT !!
Good luck.Wish me luck , I have an exam tomorrow
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