# Current, Polarity and EMF through circuit?

1. May 22, 2012

### TheWire247

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

In the circuit shown in the link, the 6.0 \ohm resistor is consuming energy at a rate of 24.0 J/s when the current through it flows as shown.

A) Find the current through the ammeter A.

B) What is the polarity and emf of the battery \epsilon assuming it has negligible internal resistance?

session.masteringphysics.com/problemAsset/1267081/1/yg.19.62.jpg

2. Relevant equations

V=IR

V=ε-IR

3. The attempt at a solution

I am completely stuck so any help would be very much appreciated

#### Attached Files:

• ###### yg.19.62.jpg
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Last edited: May 22, 2012
2. May 22, 2012

### Staff: Mentor

Your link does not appear to work. Can you please upload the JPG as an attachment? Look for the little framed painting icon in the posting window to link to a JPG.

Also, I'll move this to the Intro Physics forum. The Advanced Physics forum is for upper-division and graduate-level questions.

3. May 22, 2012

### TheWire247

Thank you, I have now attached the picture

4. May 22, 2012

### Staff: Mentor

First thing is to parallel combine the two 20 Ohm resistors in the upper left part of the circuit. That simplifies things a little. Then write the 2 KVL equations for the 2 loops in the circuit, and solve for the unknowns.

5. May 23, 2012

### TheWire247

Thank you. The problem was that I was assuming the current to be the same throughout the whole of the loops which was giving me some weird answers. Completely forgot about the junction rule.

Thank you very much for your help