Physics Lab Report on Magnetism

Physics Lab Report: Magnetism

Aim: To compare the ratio of the magnetic length, the geometric length and magnetic field strength of different shaped magnets.

Materials: * A Bar Magnet * A Horse Shoe Shaped Magnet * A Cylindrical Magnet * A Compass * Pencil * Ruler * A Wooden Board * 4 Needles * A bunch of Needles/pins * A3 Size paper

Procedure: 1. We took a wooden board and 4 needles, which we hammered to the 4 corners of the board. 2. We were given 3 different types of magnets; Bar Magnet, Horse Shoe magnet and Cylindrical Magnet and a compass. 3. I traced each magnet on the A3 size paper. 4. I started off with tracing the bar magnet and took a compass and kept it near the magnet, which then pointed towards the North and used it to draw the magnetic field lines. 5. I, later on labeled the magnet’s north pole and south pole on the paper. 6. Then I took the bar magnet and brought it right above the bunch of pins. 7. As I got it above them, the pins got attracted towards the magnet and got stuck to it. 8. Later on, I started to count the number of pins/needles, which were stuck to the magnet and got out the exact number of pins and noted down on the paper next to the bar magnet diagram. 9. I repeated the steps 4 to 8, for the rest of the magnets; Cylindrical and Horse Shoe magnet and labeled it in the same manner as I did for the bar magnet.

Hypothesis: I predict that, the bar magnet will attract the most number of pins, since it is much more stronger than the other two magnets; Horse Shoe Magnet and Cylindrical Magnet. I can also state that the Magnetic filed of the bar magnet is much more stronger, therefore can attract maximum number of metal things.

Observation Table:

Sr. No. | Type of Magnet | Magnetic Length | Geometric Magnetic | Ratio of Magnetic to Geometric | No. of pins Attracted | Relative B | 1 | Bar Magnet | 5.2cm | 7.7cm | 0.675 | 75 pins | Strongest | 2 | Cylindrical Magnet | 3.1cm | 5.7cm | 0.544 | 35 Pins | Moderate | 3 | Horse Shoe Magnet | 4.3cm | 4.4cm | 0.977 | 20 Pins | Weak |

Evaluation: The magnet attracts the pins or needles. The more number of pins attracted on the bar magnet, indicates that the magnetic field strength of the bar magnet is more as compared to the other two magnets.

Conclusion: I conclude by stating that, in magnets, the surface area does not matter, since the surface area of Horse Shoe magnet is greater, even though the bar magnet is attracting more pins. The bar magnet attracts more pins because it has a stronger magnetic field but less of surface area, whereas the cylindrical magnet has got poor magnetic field and less surface area than the two magnets, therefore the number of pins attracted to it will be less.