Electromagnetism

• at which part of a magnet are magnetic forces strongest

  poles of magnet
• what happens when two magnets are brought close to each other

  they exert a force on each other
• what type of force is exerted if two like poles of a magnet are brought near each other

  repulsive, non contact force
• what type of force is exerted if two unlike poles of a magnet are bought near each other

  an attractive, non contact force
• magnetic field


  region surrounding a magnet where another magnet or magnetic material experiences a non contact force
• what is produced when current flows through a conducting wire

  magnetic field is produced around the wire
• how do you work out direction of the field around a current carrying wire

  using the right hand grip rule
• what determines the strength of magnetic field around a current carrying wire

  . the distance from wire

  . the coils around the wire
• solenoid


  a coil of wire which when current passes through creates a strong magnetic field
• describe magnetic field found inside a solenoid


  strong and uniform
• electromagnet


  . solenoid with an added iron core

  . adding the iron core increases the strength of magnetic field
• motor effect


  when a force is exerted between a magnetic field and a current carrying conductor placed in that field
• rule used to determine the force experienced due to motor effect

  flemings left hand rule
• what does the forefinger represent

  points direction of magnetic field
• what does the second finger represent

  points in direction of current flowing in conductor
• what factors affect size of force on current carrying wire in magnetic field

  . magnitude of current flowing through conductor

  . strength of magnetic field that conductor is placed in
• if direction of current in a current carrying wire placed in a uniform magnetic field is reversed, what happens to force

  direction of force is reversed
• if strength of current in a current carrying wire placed in a uniform magnetic fields is increased what happens to the force


  the strength of force is increased
• what criteria must be met for equation linking force magnetic flux density current and length to apply

  conductor must be at right angles to magnetic field it is placed in
• equation linking force, magnetic flux density, current an length

  force = magnetic field strength × current × length
• what equation is used to link the voltage and number of turns on coils of a transformer


  V1 / V2 = N1 / N2