Experiment: investigating E field btw parallel plates using a charged foil strip In the expt., E field was set up between 2 parallel plates and a positively charged foil was placed at the middle in between. The EHT supply was adjusted so that the foil deflected 45deg for different chosen plates separation. A graph of voltage against separation was plotted and by theory, it should pass thr. origin. However, my graph has a -ve y-intercept and i can't think of a reason for it. My questions: What does a -ve voltage mean? Could it mean the plates had resistance? (since at zero separation, ie the plates touch each other, there's a -ve voltage(energy change) across it) What does the +ve x-intercept of it mean? At a certain separation, p.d. across the plates is zero? Does the slope of the curve still mean the field strength between the plates?