How do I simplify this resistor circuit for my homework?

[exitwound]

Homework Statement

Homework Equations

Resistors in Series = R1 + R2 + R3... = Req
Resistors in Parallel = 1/R1 + 1/R2 + 1/R3 ... = 1/Req

The Attempt at a Solution

Studying for a test. This sample exam went pretty well. I am having trouble with 3 out of the 20. I can't figure this one out.

The bottom branch can be combined to be Req = 30 + 30 = 60 Ohms

From there, I can't seem to find a way to combine the rest. I have the answer (B) but I can't collapse the circuit.

 

[mikelepore]

The top right resistor is shorted out, so it has no effect. Imagine that it's erased from the diagram.
The center point and point b are the same point.
You have 30 in parallel with 30 in parallel with (30+30).
1/[(1/30) + (1/30) + (1/{30+30})] = 12 ohms.

 

[kerimek]

To simplify this resistor circuit for your homework, you can follow these steps:

1. Identify any resistors that are in series (connected end to end). These can be combined by adding their resistance values together to get the equivalent resistance (Req).

2. Next, identify any resistors that are in parallel (connected side by side). These can be combined using the equation 1/R1 + 1/R2 + 1/R3 ... = 1/Req.

3. Repeat these steps until all resistors have been combined and the circuit is simplified.

In your specific example, the bottom branch can be combined to be Req = 30 + 30 = 60 Ohms. Then, you can combine the two remaining resistors in parallel using the equation above to get the final equivalent resistance.

Remember to always check your work by comparing the simplified circuit to the original one to ensure that the equivalent resistance is the same.

I hope this helps you with your homework!