MAGNETIC EFFECT OF ELECTRIC CURRENT

Annotations:

• electric current passing through wire can produce magnetism

1. magnetic field

   Annotations:

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

      Annotations:

      • 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

      Annotations:

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

   Annotations:

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

      Annotations:

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

      Annotations:

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

         Annotations:

         • concetric ciricles
      2. circular loop

         Annotations:

         • 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

         Annotations:

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

         Annotations:

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

      Annotations:

      • 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

         Annotations:

         • 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

            Annotations:

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

            Annotations:

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

            Annotations:

            • 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

      Annotations:

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

      Annotations:

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

         Annotations:

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

         Annotations:

         • if current flows in one direction
      4. electric generator

         Annotations:

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