Calculating Magnetic Field from Spin Alignment Energy Difference

AI Thread Summary
The discussion centers on calculating the magnetic field strength (B) from the energy difference between the parallel and antiparallel alignments of an electron's spin in a magnetic field. The energy difference provided is 4.50 x 10^-25 J, leading to the formula B = energy/(eh/4πm). After calculations, the derived value for B is 48.5 mT, but the poster questions its accuracy. They consider whether the issue arises from the interpretation of the energy difference between the two spin alignments. The conversation highlights the complexities in applying theoretical formulas to practical problems in magnetism.
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An electron is placed in a magnetic field B that is directed along a z axis. The energy difference between parallel and antiparallel alignments of the z component of the electron's spin magnetic moment with B is 4.50 10-25 J. What is the magnitude of B?

energy=Beh/4pim 4.5e-25 = B (1.6e-19)(6.626e-34)/ 4pi 9.109e-31

B=4.5e-25/9.27e-24

B=.0485 T
B =48.5 mT

But this seems to be wrong?
 
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I have also tried -48.5mT but that is wrong also
 
Is it because the problem is giving youthe energy difference between the two alignments?
 
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