MAGNETIC EFFECT OF ELECTRIC CURRENT

Nota:

• electric current passing through wire can produce magnetism

1. magnetic field

   Nota:

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

      Nota:

      • 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

      Nota:

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

   Nota:

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

      Nota:

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

      Nota:

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

         Nota:

         • concetric ciricles
      2. circular loop

         Nota:

         • 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

         Nota:

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

         Nota:

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

      Nota:

      • 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

         Nota:

         • 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

            Nota:

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

            Nota:

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

            Nota:

            • 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

      Nota:

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

      Nota:

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

         Nota:

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

         Nota:

         • if current flows in one direction
      4. electric generator

         Nota:

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