Finding the emf and internal resistance of a cell

[dtwazere]

I hope someone can help me with my coursework by making sure my method is ok and is actually correct for my experiment. Note. I will not actually be doing this it is just a plan of what I could do!

1. I am provided with a cell of approcimate EMF 1.5V, an approximate internal resistance of 1Ω and an approximate energy capacity of 1.5Ah. I have to plan an experiement to find the EMF and internal resistance.



2. I know that i will be using the equation ε=Ir+IR and rearranging it to give V= -Ir +ε and linking it with the general equation for a linear graph y=mx+c. I know the y intercept will be the EMF and the gradient, -r, will be my internal resistance.



3. For my method i will be setting up my experiment like this:http://img232.imageshack.us/img232/774/experimentma5.th.jpg

I want to know if my method is correct. I will turn on the cell and adjust the rehostat until i find the lowest current recorded on my ammeter. I will then read off my voltage and make a table of both readings. I will then adjust the rheostat each time so I take 10 readings of voltage and current but i will not exceed 1.5 amps. Does this method seem ok? I am confused on whether it is correct or not.

Thanks in advance for your help,

Daniel

 

[Shooting Star]

Seems pretty all right to me.

 

[ogb p]

Dear Daniel,

Your proposed method for finding the EMF and internal resistance of a cell seems to be appropriate and aligns with the equations and concepts involved in this experiment. By using the equation ε=Ir+IR, you can determine the EMF and internal resistance by plotting a graph of voltage (V) against current (I). The y-intercept of the graph will represent the EMF and the gradient will represent the internal resistance.

In your experiment, it is important to make sure that the current does not exceed 1.5 amps, as this is the energy capacity of the cell and exceeding it could lead to potential safety hazards. Additionally, it would be helpful to take multiple readings of voltage and current to ensure accuracy and precision in your results.

Overall, your method seems to be correct and well thought out. However, it is always a good idea to consult with your instructor or a more experienced scientist to confirm the validity of your experimental design. Best of luck with your coursework!