# Nodal analysis in AC circuits

Discussion in 'Homework Help' started by plaayaah, Apr 27, 2013.

1. ### plaayaah Thread Starter New Member

Apr 27, 2013
1
0
Hello, I am new to the forum, so if this has been previously answered before, please to forward me the link and I apologize for the inconvenience.

My question is that we have just started AC circuits using phasors and I understand how to carry out nodal analysis calculations in DC current, but I have absolutely no idea how I can find out the desired voltage in an AC circuit with phasors. For DC current, all I had to do was plug in the values in the 'solver' function in my graphical calculator.

I tried Google and Youtube and I could not get any successful answer, so if anyone would have the time to help a student in deep need out, I would really really appreciate it.

Either an example with a manual calculation or just a brief explanation on how to find out the voltage with the calculator would be appreciated.

Thanking you so much!
Amish

2. ### WBahn Moderator

Mar 31, 2012
22,990
6,884
This is a perfect example of the abuse of calculators in education. You were not taught how to solve DC circuit problems, you were taught how to tell a calculator to do your thinking for you and have IT solve DC circuit problems. If YOU understood how to carry out nodal analysis on DC circuits, you would know how to do it for AC circuits once you were taught how to add/subtract/multiply/divide phasors.

Unfortunately, whoever taught you DC circuits failed to lay a proper educational foundation and, as a result, you are poorly prepared to build any further education on top of it.

What you need to do is go back and learn how to solve DC circuits without your calculator -- or under the constraint that your calculator is to be used only to add/subtract/multiply/divide numbers.

You might try the E-book available here, but it is written from an electron-flow standpoint in which a positive current flow corresponds to the direction in which negatively charged particles are flowing. Thus you might find it too confusing if you are used to conventional current. But you might be best served by simply going back through your text book and redoing the DC analysis parts carefully and manually. You should find that, having been through it once, it won't take too long to pick up the parts you missed the first time around.