# MAGNETIC FIELD MAPPING: Part 1 Strength

Name: ______Period: ______

MAGNETIC FIELD MAPPING: Part 1 — Strength

1. Run Logger Pro and attach a magnetic field sensor. Set the sensor to the “6.4mT” range. Set up Data Collection (under the Experiment menu) to “Events with Entry” with the full name “Distance”, short name “X” and units “cm”. Also, double click on the graph, click on “Graph Options”, and then de-select “Connect Points”.
2. Tape the magnet (on edge) onto the axis at the location indicated.
3. At each hash mark on the axis (starting at 3 cm and increasing in centimeter intervals), measure the magnitude of the magnetic field with the sensor center on the mark and the sensor pointing along the axis (see diagram). You might find it convenient to lay the sensor on its side, as shown by the dotted line below. If the field is negative, either flip the magnet or create a calculated column in Logger Pro that makes the value positive. Once the sensor is in place, click on the “Keep Current Value” button (shown at right) and enter the distance along the axis. Measure the field at all the hashmarks.
4. Once the data collection is completed, fit the results with the power function y=Ax^B. Draw an accurate sketch of the plot below and record the values for the fit parameters A (scale factor) and B (exponent).

MAGNETIC FIELD MAPPING: Part 2 — Direction

1. Tape the magnet on edge at the location indicated on the grid.
2. Lay the sensor flat on the paper and center the sensor on each dot. Rotate the PAPER until the sensor gives the largest POSITIVE field value. This is hard — do the best you can! You will also need to switch between the “6.4 mT” and “0.32 mT” sensitivity settings on the sensor as needed.
3. Draw an arrow about 2 squares long oriented in the measured direction and centered on the dot (see sketch at right) — sorta like a compass needle. Don’t worry about magnitude for the drawing.
4. You don't really have to do every point. The field is symmetric about the midline, so once you know the field on one side of the magnet, you know the field on the other side. Confirm a couple of points with the sensor, but then just draw in the missing arrows.
5. Even harder … Sketch 3 magnetic field lines that each emerge from one end the magnet, pass through one of the open points on the center axis, and then re-enter the magnet at the opposite end. Your field lines probably won’t pass through any of the dots. But, since field lines cannot cross, you can use the field directions at the dots to put constraints on your field lines