You are Here: Home >< Physics

# Kirchhoff and his bloody laws. Watch

1. I am trying to teach myself Kirchhoff's laws for interviews this December since we weren't taught it at school. I am ok on circuits with one cell but I made this example up myself and I do not know where to go with it. I have attached a picture of said circuit with the current arrows in the direction I believe they go.

My main problem at the moment is on the connection B-E. I have two directions for current and I don't know in which way they go. Also, coming 'out of' B towards A, I don't know if the current from the cell on the far right combines with the current from the top left cell.

Attached Images

2. (Original post by tazzik)
I am trying to teach myself Kirchhoff's laws for interviews this December since we weren't taught it at school. I am ok on circuits with one cell but I made this example up myself and I do not know where to go with it. I have attached a picture of said circuit with the current arrows in the direction I believe they go.

My main problem at the moment is on the connection B-E. I have two directions for current and I don't know in which way they go. Also, coming 'out of' B towards A, I don't know if the current from the cell on the far right combines with the current from the top left cell.

Here's the circuit you posted.
I've marked in the currents and written a note on the current in EB.

It doesn't matter if you choose the wrong direction for a current.
Just be consistent with the addition and subtraction at the nodes.
When you do the calculation, if a current turns out to be negative, it just means it was going the other way to the one you initially decided.
The maths takes care of it.
3. Kirchhoffs laws are amazing. They're so damn obvious when you think about them, yet they are an incredibly useful tool in decyphering circuits.

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: December 1, 2010
Today on TSR

### Degrees to get rich!

... and the ones that won't

### Women equal with Men?

Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• Poll
Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.