scientific
8
012-04046C
Current Balance and Accessory
Procedure
1. Set up the apparatus as shown in Figure 4.1.
If you are using a quadruple-beam balance:
2. Determine the mass of the Magnet Assembly with
no current flowing. Record this value in Table 4.1
on the appropriate line.
3. Set the angle to 0
o
with the direction of the coil of
wire approximately parallel to the magnetic field.
Set the current to 1.0 amp. Determine the new
“mass” of the Magnet Assembly. Record this
value under “Mass” in Table 4.1.
4. Subtract the mass measured with no current
flowing from the mass measured with current flowing. Record the difference as the “Force.”
5. Increase the angle in 5
o
increments up to 90
o
, and then in –5
o
increments to –90
o
. At each
angle, repeat the mass/force measurement.
If you are using an electronic balance:
2. 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.
3. Set the angle to 0
o
with the direction of the coil of wire approximately parallel to the magnetic
field. Set the current to 1.0 amp. Record the mass value in the “Force” column of Table 4.1.
4. Increase the angle in 5
o
increments up to 90
o
, and then in –5
o
increments to –90
o
. At each
angle, repeat the mass/force measurement.
Data Processing
Plot a graph of Force (vertical axis) versus Angle (horizontal axis).
Analysis
What is the relationship between these two variables? How do changes in the angle between
the current and the magnetic field affect the force acting between them? What angle produces
the greatest force? What angle produces the least force?
SF-8608
Accessory
Unit
Lab Stand
Main Unit
0.01 gram
Balance
Magnet
Assembly
Figure 4.1 Equipment Setup
Angle “Mass” “Force”
(
θ
)
(gram)
(gram)
0
5
10
15
20
25
30
35
40
45
Angle “Mass” “Force”
(
θ
)
(gram)
(gram)
0
–5
–10
–15
–20
–25
–30
–35
–40
–45
Angle “Mass” “Force”
(
θ
)
(gram)
(gram)
50
55
60
65
70
75
80
85
90
–50
–55
–60
–65
–70
–75
–80
–85
–90
Angle “Mass” “Force”
(
θ
)
(gram)
(gram)
“Mass” with I = 0: _________
Table 4.1 Data
Experiment 4: Force versus Angle
