Io has to be 0 right? book answer is 800mA?!
I did get 32 for Vo
I did get 32 for Vo
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By your reasoning, the Io in the following problem would have to be zero. Right?From ohm's law... i = v/r
There is no resistence between the two 'ends' of the arrow... and the voltage on both ends is the same
The 'line' the arrow is asking about can be collapsed to a point/node... nothing to this point in the book as discussed anything about voltages/currents within a node.
Sure it has. The whole concept of KCL is based on the assertion that, absent net charge accumulation, current that enters a region has to equal the current that leaves a region. That region can be an entire node or, say, the left side of a node that connects two resistors with a horizontal piece of wire.From ohm's law... i = v/r
There is no resistence between the two 'ends' of the arrow... and the voltage on both ends is the same
The 'line' the arrow is asking about can be collapsed to a point/node... nothing to this point in the book as discussed anything about voltages/currents within a node.
But 0/0 is indeterminate.From ohm's law... i = v/r
There is no resistence between the two 'ends' of the arrow... and the voltage on both ends is the same...
Solving the problem for the OP and dishing it up on a silver platter may well be the easiest way for them to get the solution, but here in Homework Help we try to help the OP learn by guiding them toward a solution while having them do the work.The easiest way to solve this problem is as follows.
Yeah. So?But 0/0 is indeterminate.
No, it is clearly that there is a current flowing through the wire....
Does that mean either that there is no current flowing in that wire or that we can't figure out what it is?
The thing that you need to understand is that 0/0 is "indeterminate", which simply means that, based on that knowledge alone, we cannot determine what the answer is. May it is zero, maybe it is infinite, maybe it is 42, may it could take on any value in the range 50 to 2000 that is the ratio of two prime numbers. We don't know. We can't determine it based on just knowing that we have 0/0.I have another question not sure.
Does the voltage across 70Ω resistor cause charges to move and a current formed flowing through it ?
I think this is not true, otherwise the same reasoning can be applied for Io and if so then Io would be zero.
Yes, I can do it but sometimes I think why we can't apply Ohm's law for an ideal wire (zero resistance). And that is confusing.The thing that you need to understand is that 0/0 is "indeterminate", which simply means that, based on that knowledge alone, we cannot determine what the answer is. May it is zero, maybe it is infinite, maybe it is 42, may it could take on any value in the range 50 to 2000 that is the ratio of two prime numbers. We don't know. We can't determine it based on just knowing that we have 0/0.
That does not mean, however, that we can't determine the answer at all. We can use other information and other constraints to determine the answer. We do this all the time. You did it when you gave an expression for finding the current using the voltage source's voltage and the equivalent resistance of the four resistors.
My apologies; I felt that my post served an explanatory purpose. I didn't just give some mathematical answer, I explained the reasoning and logic behind this kind of problem. I felt that this was the best way to provide understanding. However, since you are 'moderating' this thread on the forum I will respect your opinion and simply avoid this thread from now on.Solving the problem for the OP and dishing it up on a silver platter may well be the easiest way for them to get the solution, but here in Homework Help we try to help the OP learn by guiding them toward a solution while having them do the work.
Consider that, most of the time, they have seen these concepts in class as well as in their textbook and have very likely seen examples worked in class and in the textbook. There is no reason to think that seeing yet one more example worked by someone else is suddenly going to make everything crystal clear. It might, but it usually won't. Instead, the person has some kind of a mental block and the best way for them to get past it is to run straight into it and have to deal with it. We can usually best help them by steering them along a path that will force them to run straight into it in such a way that it is obvious to them what it is that they have to contend with.
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