magnettttic induction questions

• How to change the milliameter

  • stronger magent
  • more coils/turns
• describe the cause of changing a magentic field in the core of a transformer

  • alternting current in the primary/secondary coil
• explain why a transformer won't work with input current

  • pd is induced by a change in a magentic field
  • a changing current is need to change a magentic field

  
• purpose of as transformer

  • step up/increase voltage
  • step down,decrease
• explain how a alternating current in a primary coil causes an alternating current in the secondary coil of a transformer

  • magentic field in the primary coil due to current
  • magentic field is altenrating/ changing in primary coil
  • the magentic field cuts through secondary coil,inducing an alternating voltage
• explain how sound is produced when an alternating coil is supplied to the coil of a loud speaker

  • alternating current produces a changing magentic field around the coil
  • the coil is in a magentic field of fixed magents
  • varying current in a magentic field produced a force on the coil which continuously changes direction
  • coil vibrates making air molecules in paper cone vibrate
• Explain how using high voltage transmission cables and transformers allows the distribution of electrical power around the United Kingdom to be as efficient as possible.

  • the voltage transmission cables voltage is lower at the destination than national grid due to loss energy through friction
  • creates a power loss (power = current 2 x resistance)
  • step up transformers increase voltage decreasing the current at the national grid so less energy is lost to friction
  • step down increase current decreasing voltage so current is free to use in our homes
• what is the name of x y and z

  x= earth

  y= live

  z= fuse

  
• <how is energy transferred through a lamp from a battery to it's surrondings

  • battery store chemical energy which is transferred to electrons to make them move
  • current = a flow of electrons,electrons collide with ions inside the metal,making them vibrate more - increasing temperutre
  • heat is dissapted to it's surrondings
• why may wires be thicker than thinner

  • thicker wires have a lower resistance,
  • less thermal energy transferred via the wires
• How can you change the induced size of the potential difference

  • increase strength of magnetic field
  • more coils
  • move the wire through the magent quicker