# Homework Help: Y/Delta Circuit Problem

1. Sep 7, 2010

### gomezfx

1. The problem statement, all variables and given/known data
[PLAIN]http://img38.imageshack.us/img38/1620/halpwd.jpg [Broken]

2. Relevant equations
I've been simplifying the circuit but with no real objective or guidance. I just don't know how to even begin to show that R and RL are equal. Can someone please help me?

3. The attempt at a solution
This is my work so far. I've just tried simplifying it, but like I said I have no real idea what to do next.
http://img706.imageshack.us/img706/6398/imggc.jpg [Broken]

Last edited by a moderator: May 4, 2017
2. Sep 7, 2010

### rl.bhat

You have already converted Y to Δ.

After simplification, new Δ consists of 3R, 3R/4 and 3R.

Again convert Δ to Y. Three sections contain R/3, R/3 and 4R/3.

So Rab = RL = R/3 + [4R/3*(R/3+RL)]/(R/3 + 4R/3 + RL)

Simplify the equation.

3. Sep 7, 2010

### gomezfx

Wow, thanks a lot!

4. Sep 8, 2010

### gomezfx

Does anyone know how I can get part B?

5. Sep 8, 2010

### rl.bhat

Total current I = vi/R.

Current through c-d branch is

T2 = I*(4R/3)/2*4R/3 = I/2

vo = R*I/2 = vi/2