Listening Part 4: Highlight correct summary

PTE Listening Part 4- Sample 2: Highlight Correct Summary

The physical phenomena which is controlled by the magnetic fields is known as magnetism. A magnetic field results when an electric current as well as magnetic moment of any elementary particle acts on some other current and magnetic moment. It is a subcategory of the phenomenon of electromagnetism and is most likely to take place in ferromagnetic materials which themselves in turn become permanent magnets when under the influence of a robust magnetic field. And just as with the help of magnetic fields, particles become magnetic, these magnets can also be demagnetised. In fact, there are only a small number of substances such as nickel, cobalt and iron along with their alloys which are ferromagnetic in nature. And it is due to this reason that the term uses ‘ferro’ as a prefix which is attributed to iron and was observed in lodestone, an iron ore known as magnetite. And even though all substances exhibit some kind of magnetism which are of various kinds, the most common is ferromagnetism. This is because the others like paramagnetism, diamagnetism, and antiferromagnetism owing to their weakened structure have a complex relation with a magnetic field and are commonly referred to as non-magnetic substances.