H H
Magnetic Forces and Fields
196
 
   
Our Force Field
is Magnetic!
 
                                                                 
               At the present rate, Earth's magnetic field could be gone within a few centuries, exposing the planet to the relentless blast of charged particles from space with unpredictable consequences for the atmosphere and life. Other possibilities: the field could stop weakening and begin to strengthen, or it could weaken to the point that it suddenly flips polarity—that is, compasses begin to point to the South Magnetic Pole.      
                           
  The Earth's Magnetic Field               Hans Christian Oersted  
           
   
   
 
   
                               
         
        Origins
         
                               
      Comparison of force due to an
Electric Field and Magnetic Field



 
                               
 
                               
 
      Magnetic Force
F  
=  qv x B
       
                                           
                     
     
                 
                                                       
   
Speaker Dynamics I
                                   
                                   
   
    A mass spectrometer
A second Mass spectrometer

ANSTO
     
                                     
Magnetic Resonance Imaging

Magnetic Resonance Imaging
Shockwave MRI
 
     
Magnetic Force on a current carying conductor
     
     
A current will make this rod move.
     
 
             
         
 
Which way will the
loop rotate?
 
         
             
 
Motors I, II, III
 
 
Notice how the force on the top and bottom segments changes just at the right time.  
 
 


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