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# Kirchoff's second law question Watch

1. Could someone tell me how to approach this question and how to correctly apply Kirchoffs first and second law in general. I haven't quite got my head around the topic and how the different currents flow through the loops.
2. (Original post by scientific222)

Could someone tell me how to approach this question and how to correctly apply Kirchoffs first and second law in general. I haven't quite got my head around the topic and how the different currents flow through the loops.
Take a look at this thread first.
It's worth a look.
It's the same question.
http://www.thestudentroom.co.uk/show....php?t=2268108
3. K the answer is 0.033 A

Here's what you do

First off apply Kirchhoffs first law, this establishes a relationship with all the different currents of the circuit.

There are three currents and there is one conjugate junction pair, thus the current is split into two at one point and recombines at another.

Thus, I(1) = I(2) + I(3)

Next use kirchhoffs second law, selecting the least complicated loops, to create 2 equations each which, in this case, relate 2 of the three currents to the EMF of each loop.

Now here is where things can go wrong, I am not sure why just yet but when you are deducing the direction of the current which run between both loops the direction of this current must be the same for each loop.

If you don't you will get the answer wrong. Now just solve simultaneously any style you like.

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Updated: July 19, 2013
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