Finding independent loops in basic circuits.

[NewtonianAlch]

Homework Statement

This was a question on my lecture slides which I didn't quite understand during the lecture.

Here is the circuit:

http://img843.imageshack.us/img843/3548/nodesbranchesloops.jpg

The question was to find independent loops in the circuit.

On the left-hand side I drew in the loops that my lecturer indicated.

This was the given definition for an independent loop:

A loop is said to be independent if it contains at least one branch which is not part of any other independent loop.

So there are 5 branches in the circuit and 3 nodes.

My initial thought of the independent loops is on the right-hand side, which was supposedly incorrect, but I don't see how it's wrong. The third loop on the right I drew has at least one branch (current source) which is not part of any other independent loop.

Also, wouldn't this entirely depend on how you draw the loops? For e.g. would this be correct?

http://img198.imageshack.us/img198/3092/nodesbranchesloops2.jpg

Thanks

 

[NewtonianAlch]

Nvm! I see why it can't be now. Making the right-hand side an independent loop would mean the middle one is no longer independent because the two resistors in parallel (branches) are shared.