MAGNETIC EFFECT OF ELECTRIC CURRENT

Anotações:

• electric current passing through wire can produce magnetism

1. magnetic field

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   • space surrounding a magnet in which magnetic force is exrted
   1. field lines

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      • lnes drawn around magnetic fieldalong with a north magnetic pole
      • strength of magnetic field depend on the degree of the closeness of the field lines
      • exist in all the planes around the magnet
      1. Properties of magnetic field lines
         1. originate at north and end at south
         2. closer near poles wide at other places
         3. do not intersect each other
   2. MAGNETIC FIELD OF EARTH

      Anotações:

      • EARTH IS A HUGE ELECTRO MAGNET IT ACTS AS A MAGNET
2. ELECTROMAGNETISM

   Anotações:

   • rise to mechanical force
   1. discovered by Oersted in 1820

      Anotações:

      • a current flowing in a wire gives rise to magnetic field
   2. field patterns produced by current

      Anotações:

      • depends on current carrying sonductor's shape
      1. straight conductor

         Anotações:

         • concetric ciricles
      2. circular loop

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         • circular near current carrying loopand straight at the centre of the circular loop
         • magnitude of magnetic field at the centr : 1 directly proportional to current  2.inversely proportional to radius of the circle
      3. solenoid

         Anotações:

         • like bar magnet
         • it is used for making electromagnet
      4. Clock face rule

         Anotações:

         • current clockwise      south pole current anticlockwise      north pole
   3. Electromagnet

      Anotações:

      • combination of selonoid and soft iron core dont use any other subs because they will became permanent magnet because of this
      • BETTER THAN PERMANENT MAGNET
      • WE CAN DTERMINE DIRECTION BY CLOCK FACE RULE
      1. works on the magnetic field of the current
      2. FACTORS AFFECTING STRENGTH OF ELECTROMAGNET
         1. NO. OF TURNS IN THE COIL
         2. THE CURRENT FLOWING IN THE COIL
         3. LENGTH OF AIR GAPS BETWEEN ITS POLES
      3. force on current carrying conductor in a magnetic field

         Anotações:

         • when a current carrying cunductor is placed in a magnetic field , a mechanical force is exerted on the conductor which can make the conductor move
         1. M. feraday

            Anotações:

            • motor principle
         2. MECHANICAL FORCE
         3. flemings left hand rule

            Anotações:

            • current, magnetic field, direction of force are perpendicular to each other
         4. THE ELECTRIC MOTOR

            Anotações:

            • device which converts electrical energy into mechanical energy
            1. USES
               1. ELECTRIC FANS
               2. WASHING MACHINE
               3. ELECTRIC CARS
               4. REFRIGERATORS
               5. MIXER AND GRINDER,ETC
            2. PRINCIPLE: rectangular coil is placed in a magnetic field and current is passes through them , force acts on the coil and coil moves
   4. MAGNETISM IN HUMAN BEINGS

      Anotações:

      • MAIN PARTS HEART AND THE BRAIN WHER MAGNETISM PRODUCE
      • produced by the movement of the charged particles called ions
   5. ELECTROMAGNETIC INDUCTION

      Anotações:

      • production of electricity from magnetism
      1. micheal feraday and joseph henry
      2. ac current

         Anotações:

         • if current reverses direction in interval of time
      3. dc current

         Anotações:

         • if current flows in one direction
      4. electric generator

         Anotações:

         • macine which converts mechanical energy into electrical energy
         1. AC
         2. DC