Question involving EMF and internal resistance

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SUMMARY

The discussion focuses on calculating the electromotive force (EMF) and internal resistance of a cell based on its current output with varying external resistances. When connected to a 5 ohm resistor, the cell supplies a current of 2 Amperes, while a 9 ohm resistor results in a current of 1.2 Amperes. Using these values, the EMF and internal resistance can be determined through the formula E = I(R + r), where E is the EMF, I is the current, R is the external resistance, and r is the internal resistance.

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Anveshan
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A cell supplies a current of 2 Ampere, when it is connected to 5 ohm resistance and supply a current of 1.2 Ampere. If it is connected to resistance of 9 ohm, find EMF(electro motive force) and Internal Resistance
 
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Anveshan said:
A cell supplies a current of 2 Ampere, when it is connected to 5 ohm resistance and supplies a current of 1.2 Ampere if it is connected to resistance of 9 ohm. Find EMF(electro motive force) and Internal Resistance

Hi Anveshan, welcome to PF.

This is your first thread, but next time follow the rules of the Forums, please. You need to use the Template provided and show what you know and what you tried in order to solve the problem. I corrected a bit the problem text. So you connect an R1= 5Ω resistance to a cell and measure the current in the loop: it is I1= 2 A. Then you change the resistance, and connect an R2=9Ω resistance to the cell: The current becomes I=1.2 A. Did you mean so?

How do you calculate the current in a loop that contains a cell with emf E and internal resistance r and an outer resistance R?

ehild
 

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