1) Circuit Setup

Figure 5

Multiple batteries will be used as a variable voltage/current source. Organize your workspace with the circuit if figure 5 so that you can easily add/remove batteries while measuring magnetic field intensities within the wire coils. Be careful not to short the batteries. Test the field of the coil, adjusting the software scaling to suit.

This lab requires fairly large currents in the wires. Do not leave the circuit on for extended times as it drains the batteries and heats the wires. Only switch the circuit on when you are making a measurement. Special caution on cleanup not to short the batteries.

2) Magnetic Field and Coil Current Experiment

To determine how the magnetic field at the center of a coil varies with the current through the coil.

Setup the circuit of figure 5 with a coil of as many loops as can be made with the length of wire given. Orient the magnetic field sensor at the coil center to measure along the expected field direction (field is measured perpendicular to the white sensor dot). Tape the sensor in place so it remains in the same position for the experiment.

Zero the sensor when no current is flowing, removing the effect of earth's magnetic field and any local magnetism. Prepare to record the data in a table along with drawing a rough graph.

Record the field for a number of different currents. Check zero with each measurement (the field of interest is the difference between current and no current). Determine the slope of your rough graph.

Relate the graph slope to the theory equations. Calculate what is expected from theory for the graph slope (if not done during the period then complete this at home and insert into your notebook during the following period).