Tape the meter stick to the top of the table so that it doesn't move easily.
Set up the stand and clamp so that the magnetic field sensor end is at
the 0 marker on the ruler. The small white spot on the end of the sensor should
be facing the magnet.
Connect the Vernier magnetic field sensor to the adapter cable and then
into the CBL unit in CH 1. Link the CBL unit and the TI graphing calculator
by connecting the black link cable into the bottom of both the CBL unit and
Prepare the CBL / sensor / calculator for data collection by entering into
the PHYSICS program and setting up the magnetic field probe. Select SETUP
PROBES, then ONE probe. To set the type of probe, select MORE and then under
the new menu choose MAGNETIC FIELD. Use the USE STORED in the calibration
menu. Select LOW (GAUSS) from the magnetic field setting menu and make sure
that the detector's switch is set to LOW.
Select ZERO PROBES from this menu, CHANNEL 1 and then press TRIGGER on
the CBL to set the zero of the probe.
From the main menu, select COLLECT DATA and use the TRIGGER/PROMPT feature.
This will allow you to move the magnet, record a reading, then enter in how
far away it was.
Start by placing the magnet 4-cm away from the magnetic field sensor by
placing it on the ruler. Find the orientation of the magnet that gives the
highest field reading. This will mean the polarization is along the meter
stick. Rotate the magnet along the meter stick so that the pole facing the
sensor gives a positive reading. After each measurement select MORE DATA and
then slide the magnet back 2 cm and take the new measurement. When prompted
for data entry on the calculator, enter in the correct distance for each measurement
Select STOP and GRAPH from the menu to see a plot of magnetic field vs.
distance. Draw the plot that you see on the calculator screen after you have
finished collecting data.
To print the graph using TI-Graph Link instead:
Disconnect the calculator from the CBL unit while the graph is displayed
on the screen of the calculator.
Connect the gray TI-Graph Link Cable to the computer's serial port
and then to the calculator's link port at the base of the calculator.
Start the TI-Graph Link Software and select LINK from the menu at the
top of the screen.
Choose GET SCREEN from the drop down menu and then when the box comes
up choose GET SCREEN again.
Reconnect the TI calculator to the CBL unit.
Fill in the data table by using the left and right arrow buttons to trace
from point to point along the graph. Read the magnetic field for each point
from the bottom of the screen.
Magnetic Field (Gauss)
Graph your data here:
What happens to the magnetic field strength as distance increases?
What would the magnetic field strength be at 7 cm?
What would the magnetic field strength be at 16 cm?
How does this help explain why the magnetic field of the earth does not
overpower the magnetic field of the bar magnet when we hold a compass to it?