Hi there, First post here guys! Recently i have been assigned my coursework on measuring the resistance of a filament lamp whereby an experiment was carried out by increasing the voltage through the filament lamp in intervals of 0.5 volts and measuring the current. I have since made a graph of current against voltage (current on Y axis and Voltage on X axis) which looks like this: http://www.gcse.com/IV_lamp.htm However, I am now analysing this graph and struggling. Why does the graph look like this? Why does the graph curve and why does the beginning of the line lok almost straight. Your help will be much appreciated Thanks!