Find the current through the 100 Ohm resistor:

[Jormungandr]

Homework Statement

Find the current through the 100 Ohm resistor:
http://imgur.com/sohdpyE

The Attempt at a Solution

So I was able to simplify the 100 and 500 resistors, as well as the 20, 20 and 10 series resistors, but I can't seem to discern at all whether any of the remaining ones are in series or parallel. I used a circuit simulator online which seems to think that the current is 53.3mA, but of course I can't even get the equivalent resistance, much less find the current. I just don't know how at all to work with circuits that have nodes like these running through them. Help is appreciated. Thanks!

 

[gneill]

Homework Statement

Find the current through the 100 Ohm resistor:
http://imgur.com/sohdpyE

The Attempt at a Solution

So I was able to simplify the 100 and 500 resistors, as well as the 20, 20 and 10 series resistors, but I can't seem to discern at all whether any of the remaining ones are in series or parallel. I used a circuit simulator online which seems to think that the current is 53.3mA, but of course I can't even get the equivalent resistance, much less find the current. I just don't know how at all to work with circuits that have nodes like these running through them. Help is appreciated. Thanks!

If you reach a point where there's no obvious way forward by way of simplification of the network, it may be time to break out KVL, KCL, and your favorite circuit analysis techniques to solve for the current.

I can see that a Y-Δ transform might "unstick" things, but it's often more effort than its worth when a little loop, nodal or mesh analysis will crack the problem quite handily without requiring any simplifications.