Im really confused with this question,
Here is the image (sorry for making you tilt your heads)
https://www.dropbox.com/sh/v6ydqbfrg20whtb/ZWR-r9ZOSH?lst#f:q17.JPG

The way i did it was like this http://www.s-cool.co.uk/a-level/ass...ifference/Finding the internal resistance.gif

However the voltmeter is over the battery, so does this mean that its the opposite and a positive gradient ???


Im confused is the way I did it correct?!?!?!?

 

I will repost the images. They are more easier to read.
Exercise:

Your solution:

You need to write the equation related between V and I. Then find the intersection points with V and I axes.

 

In both diagrams, the volt meter is measuring the EMF of the battery (the resistor doesn't generate an EMF ). So if your plot looks like what you have been told, then you are on the right track.