In Physics we're doing an experiment to see how the resistance changes with length, but I'm having extreme difficulty in the experiment: even the preliminary work!
For example, how many lengths do I need? How can I keep the current and voltage the same for each length? Everything like that. I've been off recently due to an illness and my teacher is refusing to explain it to me!
Finally, I know that as the length increases so does the resistance, but I've no idea of the "scientific knowledge" behind it!