How bullet train and circuit breaker work on the magnetic effect of current?

bullet trains:
bullet trains are also called Maglev trains..as they work with the help of powerful electromagnets which make them high speed trains ,, electromagnets are attached to 
metal lining of track 
large magnets are present inside the train 
they work on the principal that like poles repel and unlike poles attract..
circuit breakers:
it is a device which cuts the power when when there is too much current flowing through the circuits,, they are also called fuses,, they work with the help of electromagnet ,, to cut the circuit and rejoin... 

It may possibly be c i think |-/

When seismic waves hit a fault, the waves are reflected off the fault. seismograph can detect these reflected seismic waves. geologists then use these data to map the fault's length and depth