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SAI INTERNATIONAL SCHOOL
                                                        PHYSICS
                                                        CLASS X
                          Chapter: MAGNETIC EFFECT OF ELECTRIC CURRENT







               LESSON NOTES:

               Introduction


                     We already learned about heating effects of electric current in previous chapter
                       about electricity. Now in this chapter we shall study about another phenomenon
                       related to current that is magnetic effects of current.
                     Magnets and magnetism
                      The substances which have the property of attracting small pieces of iron, nickel
                       and cobalt etc. are called magnets and this property of attraction is
                       called magnetism.
                     Most of the metals like copper, gold, silver aluminium etc. are not attracted to
                       magnets.
                     History of Magnets: According to Greek legend magnetism was first discovered
                       by a shepherd named Megnes, who lived in Megnesia, Greece. ... The iron in his
                       stick and nails had become attracted to the magnetic rock. The stone was
                       named as magnetite, after the name of the shepherd or the country it was found
                       in.
                     Magnets are found naturally in certain natural rocks and can also be made
                       artificially by certain methods.
                     Artificially made permanent magnets are made in various shapes like bar, rod,
                       disk, ring etc.
                     In a bar, rod and horse shoe magnets north and south poles are dictated by
                       letters N and S or North Pole is indicated by a dot.
                     In disk and ring magnets one face is North Pole and another face is South Pole.
                     Permanent magnets are commonly used as a direction finding compass.
               What are magnetic poles?
               Magnetic poles refer to the two areas of a magnet where the magnetic effects are the
               strongest. The poles are generally termed as the north and south poles.

               Properties of magnet:

                     Like poles of magnets repel each other while unlike poles of magnets attract
                       each other.
                     A free suspended magnet always point towards north and south direction.




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