# Help with some basic circuit analysis.

#### Emehgee

Joined Aug 2, 2018
8
Hey all,

I'm currently studying electrical engineering and working through my text.

I'm quite stumped on this one problem. I don't know how to start it as for all components there is only one given.

Am I missing something?? Any help would be greatly appreciated.

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#### dl324

Joined Mar 30, 2015
17,162
Welcome to AAC!

Show your work so we can see where you're getting hung up.

#### Jony130

Joined Feb 17, 2009
5,539
I'm quite stumped on this one problem. I don't know how to start it as for all components there is only one given.
But you already have enough information. Do you know what properties a series connection and parallel connection have in a circuit?
Do you recognize any?

#### Emehgee

Joined Aug 2, 2018
8
I guess part of the problem is I didn't feel I had enough to start with but I'm guess I'll have move things around in the equations so I've started to try that.

Here's where I've gotten so far.

Welcome to AAC!

Show your work so we can see where you're getting hung up.

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#### WBahn

Joined Mar 31, 2012
30,303
Try it starting from something you know. If you were given the value of R3 but not the current flowing in it, would you have enough information to find that current?

If so, the simply use the labels R3 and I3 for that resistance and current and then get a solution that gives you I3 if you know R3 and then solve that equation for R3 instead.

#### Emehgee

Joined Aug 2, 2018
8
Try it starting from something you know. If you were given the value of R3 but not the current flowing in it, would you have enough information to find that current?

If so, the simply use the labels R3 and I3 for that resistance and current and then get a solution that gives you I3 if you know R3 and then solve that equation for R3 instead.

Ok that makes sense to me I think. Going to keep plugging away.

#### Emehgee

Joined Aug 2, 2018
8
Thanks for the help. I think I was looking at too much from the circuit analysis side and not considering maths and algebra enough. Didn't think they'd put such a tricky question so early on.

#### dl324

Joined Mar 30, 2015
17,162
Thanks for the help. I think I was looking at too much from the circuit analysis side and not considering maths and algebra enough. Didn't think they'd put such a tricky question so early on.
It's a simple series, parallel circuit that would be covered in a first term course.

#### Emehgee

Joined Aug 2, 2018
8
It's a simple series, parallel circuit that would be covered in a first term course.

Lol. What a useless condescending reply. Thanks for your help bud.

#### dl324

Joined Mar 30, 2015
17,162
Lol. What a useless condescending reply. Thanks for your help bud.
You need to check your attitude at the door. I was just stating a fact. I had problems with series and parallel circuits at first, so don't feel bad.

If you'd take the time to show your work, we might be able to help you.

#### Emehgee

Joined Aug 2, 2018
8
You need to check your attitude at the door. I was just stating a fact. I had problems with series and parallel circuits at first, so don't feel bad.

If you'd take the time to show your work, we might be able to help you.
I showed my work when you asked the first time. I've figured it out already and thanked folks since. I didn't have any issues with the circuit analysis part it was more the maths I was missing. Just seemed a strange final comment to make to me.

#### dl324

Joined Mar 30, 2015
17,162
I showed my work when you asked the first time. I've figured it out already and thanked folks since. I didn't have any issues with the circuit analysis part it was more the maths I was missing. Just seemed a strange final comment to make to me.
There is no calculation for R3.

My comment was in response to you describing the problem as "tricky" for being "early on".