Current, Polarity and EMF through circuit?

AI Thread Summary
The discussion focuses on solving a circuit problem involving a 6.0-ohm resistor consuming energy at a rate of 24.0 J/s. Participants are tasked with finding the current through an ammeter and determining the polarity and emf of a battery with negligible internal resistance. One contributor suggests simplifying the circuit by combining two 20-ohm resistors and applying Kirchhoff's Voltage Law (KVL) to solve for unknowns. They also note a common mistake of assuming uniform current throughout the circuit loops, highlighting the importance of the junction rule. The thread emphasizes the need for clarity in circuit analysis to arrive at accurate solutions.
TheWire247
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Homework Statement



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

Homework Equations



V=IR

V=ε-IR

The Attempt at a Solution



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

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TheWire247 said:

Homework Statement



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

Homework Equations



V=IR

V=ε-IR

The Attempt at a Solution



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

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.
 
Thank you, I have now attached the picture
 
TheWire247 said:

Homework Statement



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

Homework Equations



V=IR

V=ε-IR

The Attempt at a Solution



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

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.
 
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
 
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