I think when I did this experiment I changed the variables
and
.
The equipment set up was as follows:
View attachment 34478
When changing the variable
1. When you turn the power supply on, adjust the rheostat so that it reads around 1A. Then turn the power supply off.
2. Before you turn the power supply back on, hold the permanent magnets either side of the aluminium strip (one north pole facing one side of the strip and a south pole facing the other side). You can also use the right hand palm to predict in which direction the aluminum strip will move before turning the power supply back on.
3. Turn the power supply back on and you should see that the foil experiences a force in a certain direction. Record results and then turn your power supply off.
4. Repeat steps 1-3 but this time use 2A, 3A, 4A and 5A. You can change the current by adjusting the rheostat around. The greater the current, the stronger the deflection the aluminium strip should have in the same direction.
When changing the variable
1. Use the same apparatus from the previous experiment
2. Switch the current on and adjust the rheostat such that the ammeter reads 5A
3. Switch the current off and hold the magnets either side of the foil (with a north pole near one side of the foil and a south pole near the other side) such that the magnets are 1 cm away from the foil.
4. Switch the current back on and observe the effect on the aluminium foil. Record results.
5. Repeat steps 3 and 4 several times but this time move the magnets closer towards the coil to around 0.75, 0.50 cm, 0.25cm and 0.10cm for each respective repeat.
Changing the distance of the magnets from the aluminium foil is effectively changing the magnetic field strength around the foil. The magnitude of magnetic field strength decreases with distance.
Hope that helped!