IGCSE Physics Magnets and Currents

IGCSE Physics Magnets and Currents

1. DC motor

   • Commutator
     • allows motor to keep turning
     • switch + to - , vice versa
   • drill, whisk, handheld fans

2. Transformers

   • transforms one voltage into a higher or lower voltage
   • primary coil
   • secondary coil
   • works by electromagnetic induction
     • Changing magnetic field generates or induces voltage in wire or cell
     • magnetic field around the coil is changing
   • step up transformer step down transformer

3. Attraction and Repulsion

   • N attracted to S
   • S and S repel each other
   • N and N repel each other

4. Generator/dynamo

   • works by rotating coil in a magnetic field
   • slip-ring communicator
     • produces alternating current

5. right-hand grip rule

   • into page
     • cross on arrow
   • out of page
     • arrowhead

6. Fleming's left hand rule

   • FMC
   • for d.c.
     • generator
       • right-hand rule