transformers

• step up = increases voltage to decrease I and reduce energy lost as heat
• step down = decreases voltage for safety
• 1st coil = primary or input
• 2nd coil = secondary or output
• iron core is laminated
• the electricity that goes through output goes to the national grid
• more loops on output = step up
• more loops on input = step down
• step down transformer is placed between power lines and houses
• turns is a substitute for coils

  
• iron core is laminated to

  • hold coils in place and allows magnetic fields to combine
  • iron increases strength of magnetic field because it is magnetic -> stronger magnet
• iron core is laminated in thin layers of plastic: plastic stops iron from conducting electricity and stops it from overheating -> stops eddy currents
• label with secondary and primary and number of coils and Voltage

  A) primary

  B) secondary

  C) voltage

  D) number of coils

  
• why must there be an alternating input Voltage for the transformer to work

  alternating voltage produces an alternating current. An a.c. produces a changing magnetic field (so field lines are cut)
• state how the construction of a step-down transformer is different from a step-down transformer


  the step-up has less coils on the input than the step-down transformers
• why is V produced when the coil spins?

  when the coil spins it cuts through the field lines and produces voltage
• more coils on input = less V in output
• less coils in input = more V on output