# Homework Help: Need help with Parallel circuits

1. Sep 5, 2010

### fcb

1. The problem statement, all variables and given/known data

2. Relevant equations

V=IR and What not

3. The attempt at a solution

I have attempted it many different ways
I need your help, I have preliminary exams coming up, Please do me a favour.

Regards, FCB

2. Sep 5, 2010

### rl.bhat

Show at least one attempt.

3. Sep 5, 2010

### fcb

ok so we have 5 ohm and 20 ohm , in parallel, which are both in series with 50ohm

now for equivalent resistance in parallel

1 / R eq= 1/R1 + 1/R2

ie R eq= R1 * R2 / ( R1+R2)

therefore we have ( 4ohm in series with 50 ohm)

then R eq= 54ohm ( add them when in series )

then apply v=IR to get total current in circuit

I= V/R
= 12 / 54

now when this current gets to the section where it splits in two, the current is divided and the majority of current goes throguh the least resistance

current through 5ohm = 20 / ( 25) * 12 / 54
current through 20ohm = 5 / ( 25) * 12/54

4. Sep 5, 2010