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Hello students today  we will discuss the concept of  magnetism and matter before  going to the concept  of  magnetism and matter  I would like to give you certain  key points  regarding the magnetism  that is  history of magnetism once magnets was hoarding  his  sheep in an area northern Greece  called magnesia  suddenly both the nail of his shoes and metal tip of his staff  become  firmly stuck to the large black rock on which he was standing . he was very curious to know fact behind it there for to find the source of attraction he dug up the earth and he finds load stones this is how the load stones look like . A load stones which contains magnetite and natural magnetic material Fe3O4 students keep in mind again a load stone which contains magnetite which is nothing but a natural magnetic material fe3O4. Okay fine .So the directional property of magnet was also known since ancient times  that is freely suspended  magnet and the magnet which placed on piece of cork allowed to float still on water always pointed in the north to south direction this is how can we recognize the direction of property of magnet  a freely suspended magnet  and the magnet which placed on a piece of cork  on floating still water north to south direction ok they have also use this magnet in many application one of the application will see now, you can look at the image the image is chariot with that magnetic idol is suspended the craft man build a chariot on which they place the magnetic figure which swiveled around so that the finger of the statuette on its  always pointed south. With this chariot huangti troops were able to attack enemy from the rear in thick fog and defeat them this was one of the application in the earlier days using magnets and the latest science suggest that moving charges or electric current produce magnetic field moving charges or electric current produce magnetic field this discovery was credited to the scientist oersted  ampere , Biot and savart . dear students now will discuss the common ideas regarding the magnetism  that is the first one is the earth behaves as a magnet  with magnetic field pointing approximately from geographical  south to geographical north . what is that mean  on the whole we can treat as the magnet  where the magnetic field pointing approximately  from geographic south to the geographic north next, when bar magnet is freely suspended it points the north south direction this property you know when the bar magnet freely suspended it always points in what north and south direction ok that tip which points the geographic north is called north pole and the tip which geographic sounds is called south pole u can observe the tip which point the geographic north is north pole and the tip of geographic south is south pole ok the next point is like an electrostatic here also you can get also properties likes poles ripple each other what does that mean if you bought two bar magnets of same poles , if u bought a bar magnets  of same poles each other those two bar magnet tend to ripple one and other why it so  because the between those two same poles repulsive force exist in the same way unlike pole attract each other that means if you bought two bar magnets of opposite poles those two bar magnets always attract each other and that is because of the attractive forces exist between the opposite poles so that on whole I can conclude like  poles ripples each other and unlike poles ripples  attract each other and next point is magnetic monopoles do not exist  what does mean magnetic monopoles do not exist  which is nothing but if u cut a bar into a  N equal pieces each one will be having both south and the north poles that means if u consider a bar magnet and make it into N slices in the number of slices each slices what u  have what time will be always facilitated with the two poles that is north pole south pole , north pole south pole  there for we can say that magnetic monopole do not exist ok the next point is it is possible  to make magnet out of iron and its alloys yes we can manufacture magnet with the help of iron and its alloys for example the manufacture of alnico magnets uses iron and its alloys alnico is nothing but what aluminum nickel and cobalt ok the further discussion will be in the next module . Till then keep  learning thank you.

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2017-04-18T04:55:19+00:00 Categories: PU-2|Tags: |0 Comments
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