The Physics Of Bar Magnets - 2533 Words

1. Bar magnet is the simplest form to explain magnetism. Bar magnets are permanent magnets and this means that they have magnetism all the time, it can’t be turned on and it can’t be switched off. They have two poles that include: north-seeking pole (N) and south-seeking pole (S). These poles appear to occur in equal and opposite pair. Magnetic meridian is the vertical plane in which the magnet lies. Magnets are made of materials that can be magnetized, which are also the ones that can be attracted to magnet, which are called ferromagnetic materials. These include: iron, steel, nickel, cobalt, some alloys of rare earth metals and some naturally occurring minerals such as lodestone. Mu-metal is a nickel based soft magnetic alloy,†¦show more content†¦Small bar magnets that are responsible for a magnetic behaviour are actually groups of atoms. Electron particles show magnetic behaviour of their motion – each electron has a magnetic moment. Groups of these atoms form small domains, in which the magnetic moments of the electrons are aligned with each other. When material is non-magnetised the domains are aligned in random way so their magnetic field cancels each other out. Properties of a simple bar magnet: 1. Unlike poles of magnet attract each other 2. Like poles of magnet repel each other 3. The force of the attraction of a magnet is greater at its poles than in the middle. 4. If a bar magnet is suspended by a thread and if it is free to rotate, its south pole will move towards the north pole of the earth and vice versa. A magnetic field is the magnetic effect of electric currents and magnetic materials. The magnetic field at any given point is specified by both a direction and a magnitude (or strength); as such it is a vector field. A magnetic field may be plotted by using a plotting compass to define the lines of force. Bar magnet is placed on a sheet of white paper. Starting near one end of the magnet, the positions of the ends of the compass needle are marked by pencil dots. The compass is then moved until the near end of the needle is exactly over the dot furthest from the magnet and a