Two cells in series with internal resistors -- calculate the current

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Homework Help Overview

The discussion revolves around a problem involving two cells in series, each with internal resistors, and the calculation of current in the circuit. Participants are exploring the implications of the circuit configuration and the application of Ohm's Law (V=IR).

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants are discussing the need to accurately represent the circuit and its components, questioning how to apply V=IR given the presence of two different currents. There are inquiries about the implications of the voltmeter's resistance and the circuit's configuration.

Discussion Status

The discussion is ongoing, with participants seeking clarification on circuit representation and the relationships between components. Some guidance has been offered regarding the need for a proper circuit diagram, but no consensus has been reached on the interpretation of the problem.

Contextual Notes

There are indications of confusion regarding the circuit layout as described in the original problem statement versus the circuit diagram provided by the original poster. Participants are also noting the constraints of the forum regarding the level of help that can be provided.

lalallaland
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Homework Statement
A secondary cell having an e.m.f. of 2V and an internal resistance of 1ohm is connected in series with a primary cell having an e.m.f. of 1.5V and an internal resistance of 100ohm the negative terminals of each cell is connected to the positive terminal of the other cell. A voltmeter having a resistance of 50ohm is connected to measure the terminal volatage of the cells. Calculate the voltmeter reading and the current in each cell.

Ans given by book:72.8mA, 34.3mA, 1.93V
Relevant Equations
Kirchhoff law
Can somebody explain this please? I don't understand this.
 
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Welcome to the PF.
lalallaland said:
Can somebody explain this please? I don't understand this.
How about you draw the circuit as described and attach it to a reply? Label the voltages and resistances in the loop, and show us how you can use the equation V=IR to work toward the answer. (We aren't allowed to provide tutorial help here until you show your best efforts). Thanks
 
Hey Berkeman,

Thanks a lot for your answer. I'm really stuck at this problem and it is not leaving my mind. I don't really know how to use V=IR here cause the answer tells me there are two different currents.
 

Attachments

lalallaland said:
the answer tells me there are two different currents.
You are given the resistance of the voltmeter. What does that imply?
 
However the circuit you supplied does not match that description.

Could you explain this statement? Because I think my circuit matches the description.
 
If I am reading your circuit correctly, the negative terminal of the 1.5V cell is correctly connected to the positive of the 2V cell. The negative of the 2V cell is connected to ... Where?
 
It's very helpful to actually display text and/or graphics being referred to. Here is the circuit given by OP.
1569731019165.png
 
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