magnetism and motor exam style questions

• • describe how a student can investigate how the size of the current in a solenoid affects the attraction between the solenoid and an iron nail
  • measure the length of a spring before current is on
  • use an ameter to measure the current
  • calculate the extension of the spring
  • repeat with different with different circuits

  
• How can a student develop an investigation to test the theory that two magents on top of each other is stronger than 1 magnet

  • move the brick towards the car
  • until the car starts to move
  • measure distance
  • repeat with two magents and compare
• a student has a power pack,long wire,stiff card, iron fillings.How can they show the shape of a magentic field produced by a current in a wire

  • put a wire through the card
  • put iron fillings around the wire
  • connect wire to a power pack
  • fillings attracted to see if wire attracts them
• How can u show earth has a magentic field

  • use a compass
  • will all point in the same north direction