Magents + motor effect

• what is a magnetic field

  • a region where magents experience a focre
• Magnet properties

  • non contact force
  • poles
  • attract/repel
• What is a uniform magnetic field

  • where the strength of the field is the same everywhere
• How can u plot compasses

  • place a compass on a piece of paper
  • move the compass around the page noting the direction each time
  • join up the lines
• How to draw a magnetic field

  • field lines out from the north into the south
  • magentic field lines more = more strength
• What is an induced magnetic

  • a material that becomes magnetic inside a magnetic field
• a permant magnet....

  makes its own magentic field
• What is a solenoid

  • a current flowing through a coil of wire
• describe the force of the magnetic field inside and out side the solenoid

  • each coil has it's own field,the coils inside the solenoid are strong and uniform but the coils outside the solenoid are weak because they overlapp and making it wea
• How can u increase the strength of an electromagnet

  • add more coils
  • soft iron core
  • increase the current
• what is Flemming right hand rule

  • a rule to see the direction of a current
  • if a current is going up the thumb is pointed up and out current goes anticlockwise
  • down thumb down current would be clockwise
• What is an electromagnetic

  • solenoid with a soft iron core
• How can you change the direction of a solenoid

  • reversig the current which flips the poles
• What is the motor effect

  the force exerted between a magentic field and a carrying conductor

  the force is in the same direction of the current

  current in through positive out through negative

  force = b(magentic fleux density in tesnla / n/a) x I (current in amps
• What is a split ring comminatory

  • used in electric motors
  • swaps the positive and negative each turn
  • causing the direction to swap and the current to always being the same
• iow does a split ring commentator work

  1. The split-ring commutator swaps the positive and negative connections every half  turn.
  2. Therefore, the direction of the current  through the coil reverses every half turn.
  3. This means that the forces acting on the coil will always be acting in the same direction.
  4. This causes the coil to rotate continuously in one direction.