The science class were asked to investigate the relative strength of the magnetic field at the north pole of a bar magnet before it was cut in half, and after it was cut in half. They measured the relative strength by counting the number of paper clips that could be suspended from the north pole of the magnet, and its "half magnet". 2.1 Draw a neat sketch of the magnetic field of a bar magnet. 2.2 Explain how the paper clips are attracted to the bar magnet. 2.3 Give one reason why this method of using paper clips is a fairly good indicator of the field strength. 2.4 Give one reason why this method could produce faulty results. 2.5 Predict the outcome of this experiment. Justify your answer. One group of learners found it very difficult to cut their bar magnet in half. They decided to place it on a stone (outside) and to saw through the magnet with an electrically powered saw. The bar magnet vibrated significantly during this process. When they tested their "half magnets" they found that no paper clips could be suspended from either of the pieces, whereas before cutting the magnet it had suspended 6 paper clips. 2.6 Explain what could have happened to cause these results. (2) (3) (2) (4) (4)
