Results
Experiment One: Variable = Voltage
In experiment one, I used batteries with different voltage ratings to change the voltage supplied to the electromagnet coil. I used ferrofluid in a petri dish to make the magnetic field visible. The graph for experiment one shows that as voltage is increased, the strength of the magnetic field gets stronger. You can see this because the field grows taller.
Experiment Two: Variable = Current
In experiment two, I used a potentiometer (a variable resister) to control the current from the batteries that I used in experiment one. Using the potentiometer, as resistance is taken away, the current gets stronger. The graph for experiment two shows that current affects the magnetic field because less resistance had to be removed when there was more current available.
Experiment Three: Variable = weight on surface of ferrofluid and current to coil
Finally, in experiment three, I floated a smaller petri dish on top of the ferrofluid. Then I added plastic weights to see if the ferrofluid could lift the smaller petri dish and extra weight, too. The graph for experiment three shows that the extra weight made no difference in the height of the lift for at least six grams of weight.