Eddy Current
Senior Member
Why would you ever use Kirchhoff's Law instead of Ohms Law? Is Kirchhoff's Law just to prove Ohms Law or is there a time when you would have to use Kirchhoff's Law and not be able to use Ohms Law?
Why would you ever use Kirchhoff's Law instead of Ohms Law? Is Kirchhoff's Law just to prove Ohms Law or is there a time when you would have to use Kirchhoff's Law and not be able to use Ohms Law?
Though some similarities Kirchoff's Laws focus on different details than Ohm's law.
Both Kirchoff's laws and Ohm's law are necessary to solve voltage/current problems.
Let us first see the OP has become familiar with Mr.Ohm and Mr.Kirchoff.Don't forget Thevenin & Norton and their contributions to circuit analysis.
They are both useful and although there is some overlap in what you can calculate with them, they are not completely interchangeable.Why would you ever use Kirchhoff's Law instead of Ohms Law? Is Kirchhoff's Law just to prove Ohms Law or is there a time when you would have to use Kirchhoff's Law and not be able to use Ohms Law?
A theorem is deductive and a law is empirical and proved every time the prescribed conditions are met. I think laws are interchangeable but theorem's are not 100% interchangeable with laws. You could use Kirchoffs Law in place of Ohms Law by not having to use Ohms law to find the current at every point of a series circuit, for example. Actually, one is probably a "prescribed condition" that has to be present in order to declare the other a Law? I think Ohms can exist without Kirchoffs, but Kirchoffs cannot be proven without Ohms law.
You must remember that a power source will also have an impedance. Connect a 1.5 volt battery in parallel with a 6 volt battery and no other components and the 1.5 volt battery essentially becomes a load to the 6 volt battery doesn't it?Ok i see now where i would have to use one to use the other but where i could not use just Kirchoffs law on a circuit problem without having to use Ohms Law as well.
Another question is some of the Kirchhoff's examples show two power sources. Can you use Ohms law on a circuit that has two power sources and how is that not back feeding?
I would say in most cases this is true, but put two sources in parallel and connect two loads in parallel to those sources and you have a circuit that really has no series component, so I say it is not always the case.Also in Kirchoffs law the closed circuit will always be broken down to a series circuit right?
Also in Kirchoffs law the closed circuit will always be broken down to a series circuit right?
Kirchoff and Ohm are two tools, like a slotted and a Phillips screwdriver. There are screws that you can deal with only with one or the other, some that are merely easier with one than with the other, and some where you can use either with equal effort. To be effective in dealing with screws in general you need them both in your toolbox.
That's what I said, innit?The electrical laws and theorems(tools) of Ohm, Kirchhoff, Thevenin, Norton and Maxwell are all tools to be used creatively in solving for electrical quantities and performing circuit analysis, either separately or in combination.
Generally they are used complementary to each other.
That's what I said, innit?
We are in agreement.
My statement was in support of your statement.