Find EMF of a battery in this circuit

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Homework Help Overview

The discussion revolves around finding the electromotive force (EMF) of a battery within a circuit that includes two batteries in parallel. Participants are exploring circuit simplification techniques and applying Kirchhoff's Voltage Law (KVL) to analyze the circuit.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants are questioning the simplification of the circuit, particularly regarding the configuration of the two batteries in parallel. There are inquiries about how to approach the circuit analysis when the switch is open and whether the calculated equivalent resistance of 98.9 is reasonable.

Discussion Status

The discussion is active, with participants seeking clarification on circuit simplification and the application of KVL. Some guidance has been offered regarding drawing the circuit for different switch positions, but no consensus has been reached on the approach or calculations.

Contextual Notes

Participants are working under the constraints of homework rules, which may limit the information they can share or the methods they can use. There is an emphasis on understanding the circuit configuration before proceeding with calculations.

jdmaxwell02
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Homework Statement
In the circuit below R=53.0 Ω and assume both batteries have zero internal resistance and the voltmeter and ammeter are ideal. When the switch is open the voltmeter displays 14.2 V.



Find the emf e m f of the unknown battery: ___ V

If the switch is closed what does the ammeter display? ____ A
Relevant Equations
EMF-Ir=IR?
1585098373348.png
 

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why did you stop where you did in simplifying the circuit?

EDIT: oh, wait ... I see now. You didn't simplify the circuit at all, you drew the two cases.

Simplify the circuit in each case and you can work it down to numerical answers.
 
phinds said:
why did you stop where you did in simplifying the circuit?

EDIT: oh, wait ... I see now. You didn't simplify the circuit at all, you drew the two cases.

Simplify the circuit in each case and you can work it down to numerical answers.

The two batteries in parallel are kinda confusing me. How would I simplify that? Also, I got 98.9 for the equivalent Resistance. Does that seem correct?
 
jdmaxwell02 said:
The two batteries in parallel are kinda confusing me. How would I simplify that?
First, draw the circuit when the switch is open. With that information, can you find the unknown emf using KVL?
 
Last edited:

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