# Simple circuit, find equivalent resistance seen by the source

1. Oct 3, 2012

### qpham26

1. The problem statement, all variables and given/known data
For the circuit shown in Figure, ﬁnd the
equivalent resistance seen by the source. How much
power is delivered by the source?

http://sphotos-b.xx.fbcdn.net/hphotos-snc7/304377_496325960386924_988412599_n.jpg [Broken]

2. Relevant equations
Req = R1R2 / R1+ R2

P = V^2 / R

3. The attempt at a solution
I am not understanding what they meant by "seem by the source"
so I assume that they want to find R equivalent for the whole thing.

Start from the right to left
2Ω + 1Ω = Req1 = 3Ω
Req1 || 3Ω = Req2 = 1.5Ω
4Ω + 1.5Ω+5Ω || 6Ω = Req3 = 3.82Ω
---->ReqS = 3.82Ω + 7Ω = 10.82Ω
---->Ps = Vs2/ ReqS = 18.11 W

Last edited by a moderator: May 6, 2017
2. Oct 3, 2012

### CWatters

.

Yes that is correct.

Imagine you were physically standing on the symbol for the 14V source voltage. What equivalent resistance do you "see" if looking to the right.