Sources of Magnetic Field

The study of magnetic field of magnets and current-carrying materials was conducted.

The experiment consists of three parts. In the first part of the experiment, the magnetic field of both the horseshoe magnet and the bar magnet was examined. The magnetic fields at different points near and on the surface of both magnets were measured and recorded using a magnetic sensor connected to LabQuest. A comparison between the data was made.

Magnetic field around a horseshoe and a bar magnet

Iron filings scattered in a sheet of paper with a horseshoe magnet underneath

Iron filings scattered in a sheet of paper with a bar magnet underneath

            The second part of the experiment aims to find out the magnetic field lines produced by a horseshoe magnet and a bar magnet. Iron filings were scattered in a sheet of paper to serve as indicators of the magnetic field lines. In one set-up, a horseshoe magnet was placed beneath the sheet of paper. Using a camera the representation of the magnetic field was recorded. A bar magnet was used on the other set-up.

            The third part of the experiment studies the magnetic field that runs through a charged coil of metal wire. The effect of the position, current and the length of the wire to the magnetic field were studied. In determining the effect of position, the coil of metal wire was stretched in to a length of one meter. Using the magnetic sensor and LabQuest the magnetic field of the coil was measured in 10cm intervals, starting from -10cm up to 120cm. To determine the effect of current, the magnetic sensor was placed 50cm from the edge of the coil. The current that runs through the coil was increased by 0.5A from 0.5A to 2.5A. The magnetic field at every 0.5A interval was recorded. To determine the effect of the length of wire to the magnetic field, the wire was compressed and stretched to a length of 25cm up to 125cm with a 25cm interval. The magnetic field at which was taken by placing the sensor in the middle of the wire.

It was found out that the magnetic field of both a horseshoe and bar magnet at one of its pole would be the same around that pole and that the magnetic field is zero at the middle of the magnet, the magnetic field lines would be the same as the electric field lines and the theory, the magnetic field that runs through a charged coil of metal wire is parabolic where the highest value is at the middle of the wire, the relationship between the current and the magnetic field is directly proportional while the relationship between the magnetic field and the length of wire is inversely proportional