Magnetic Fields
...produced by a C-shaped electromagnetic. The magnetic field was measured using two methods. First we measured the force exerted on a current carrying rod. We then measured the difference of a magnetic flux through a search coil both inside and outside of a magnetic field. We observed a large discrepancy between the two methods for obtaining values for the magnetic field.
Procedure:
For the first method of obtaining the magnetic field B, we measured the force exerted on a current-carrying conductor. A horizontal conducting bar was placed it between the positive and negative ends of an iron C-shaped electromagnet. The conducting bar was attached to a plastic scale and we used metal washers as counterweights on the other end. A diagram of the apparatus is shown below:
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For each set of trials, the current I through the electromagnet would be held constant while we varied the amount of weight placed on the balance. Using the equation F = mg, we were able to calculate the force acting on the balance. By adjusting the amount of current i traveling through the conducting rod we were able to balance the level was level, thus equaling the forces acting on the balance. With the forces equal, we could use the equations F = mg and F = iLB to solve for the magnitude of the magnetic field B. We conducted five trials, using different weights, and currents through the conducting rod while keeping I constant. We conducted a total of 20 trials at four different currents I. To calibrate the balance we marked the “level” position with no current in the electromagnet or conducting rod. When taking measurements, we made sure to measure the scale against the level position at eye level to minimize any systematic error caused by the parallax effect. The reflection of the balance was flush with the level mark and the actual balance itself.
In the second half of the lab we...
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