Ohm's law
http://www.ilsitodi.it/phisics_laboratory/ohms_law/ohms_law.html
Click the button "change resistor" to generate a random resistance between 1000Ω and 2000Ω
Moves the cursor of the power supply slider and read the voltage across the resistor and the current flowing through it. Repeat the measurement several times. Transfer the experimental data to an Excel spreadsheet and analyse the results. Prove the validity of Ohm's law:
The voltage across a resistor is directly proportional to the amount of electric current through it (for any given temperatur).
Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship:
V=R*I