Hi,
Currently studying AQA Physics A, year 12. I have my Unit One exam coming up soon and am just reviewing the content. When given a question such as this:
'The p.d across the terminals of a cell was 1.1V when the current from the cell was 0.20A, and 1.3V when the current was 0.10A. Calculate a) the internal resistance of the cell and b) the cells' e.m.f'
I correctly answered the first part of the question, by essentially taking a gradient. Do I actually need to plot a graph for the second part, or is there another way to work it out? As far as I'm aware, on a graph of terminal p.d vs. current the emf is when you extrapolate back so the terminal p.d is zero?
Finally, has anyone got any good electricity resources that explain the content quite simply? Thank you :P