Literature about graphs includes many discussions about whether zero needs to be included on all scales. We demonstrate that a graph designer can mislead just as much by changing the aspect ratio.

You should be able to recognise the graph of current against voltage for a diode. The diode has a very high resistance in one direction. This means that current can only flow in the other direction.

Learn about and revise electrical circuits, charge, current, power and resistance with GCSE Bitesize Combined Science. ... OCR 21st Century Current-voltage graphs.