Solving Current in a Cell: Use I = V/R to Find 2/3

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Homework Help Overview

The discussion revolves around calculating current in a circuit using the formula I = V/R, specifically in the context of a cell with negligible internal resistance. Participants are exploring how to arrive at a specific answer of 2/3 for the current.

Discussion Character

  • Exploratory, Assumption checking, Mathematical reasoning

Approaches and Questions Raised

  • Participants are attempting to use sample values for resistance and voltage to calculate current. There is a discussion about the equivalent resistance in a parallel circuit and how it relates to the overall current calculation.

Discussion Status

Some participants are providing calculations and questioning the steps taken to reach the answer. There is an indication of productive dialogue as participants are encouraged to express their reasoning with symbols rather than just numerical values.

Contextual Notes

There is mention of using sample values for resistance and voltage, and the discussion includes checking assumptions about internal resistance and the setup of the circuit.

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Trying to work out how to do this. I know the answer is B but don't know how.

Internal resistance is negligible so I assume I just use I =V/R. I've tried using sample values for R eg 5 and V =10V giving I as 1.3 but am no closer to 2/3. What am I missing?
 
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Can you show how did you do it with sample values? How do you calculate the current?
 
If R=5ohms

1/5+1/5=0.4

1/0.4 = 2.5 ohms in parallel

2.5 + 5 = 7.5 ohms total

If v is 10v

I = v/R = 10/7.5 = 1.333333
 
And this is compatible with answer b, isn't it?
Try to calculate 2e/3R. How much is it?

You have the right idea. Now just do the same thing with symbols rather than numbers.
What is the equivalent resistance, in terms of R?
 
Got it! Many thanks
 

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