Experiment 3: force versus magnetic field – PASCO SF-8607_08 Basic Current Balance User Manual
Page 11
scientific
7
012-04046C
Current Balance and Accessory
Procedure
➀
Set up the apparatus as shown in Figure 2.1. Use the shortest length current loop.
If you are using a quadruple-beam balance:
➁
Mount a single magnet in the center of the holder.
➂
With no current flowing, determine the mass of the Magnet Assembly. Record this value in
the first column under “Mass” in Table 3.1 on the appropriate line.
Set the current to 2.0 amps. Determine the new “mass” of the Magnet Assembly. Record
this value in the second column under “Mass” in Table 3.1.
➄
Subtract the mass you measured when there was no current flowing from the value you
measured with current flowing. Record this difference as the “Force.”
Add additional magnets, one at a time. (Make sure the north poles of the magnets are all on
the same side of the Magnet Assembly.) Each time you add a magnet, repeat steps 3-5.
If you use an electronic balance:
➁
Use a single magnet, centered under the center of the holder.
➂
Place the magnet assembly on the pan of the balance. With no current flowing, press the
TARE button, bringing the reading to 0.00 grams.
Now turn the current on, and adjust it to 2.0 amps. Record the mass value in the “Force”
column of Table 3.1.
➄
Add additional magnets, one at a time. (Make sure the north poles of the magnets are all on
the same side of the Magnet Assembly.) Each time you add a magnet, repeat steps 3-5.
Data Processing
Plot a graph of Force (vertical axis) versus Number of Magnets (horizontal axis).
Analysis
What is the relationship between these two variables? How does the number of magnets
affect the force between a current-carrying wire and a magnetic field? Is it reasonable to
assume that the strength of the magnetic field is directly proportional to the number of
magnets? What would happen if one of the magnets were put into the assembly backwards,
with its north pole next to the other magnets’ south poles? If there is time, try it.
Experiment 3: Force versus Magnetic Field
”Mass”
Number of
I = 0
I
≠
0
“Force”
Magnets
gram
gram
gram
4
5
6
Table 3.1 Data
”Mass”
Number of
I = 0
I
≠
0
“Force”
Magnets
gram
gram
gram
1
2
3
➅
➃
➃