Unformatted text preview: r = R e = 6370 km. Thus, B = Âµ Âµ 4 Ï€R 3 E q 1 + 3 sin 2 Î» m = ( 4 Ï€ Ã— 10 âˆ’ 7 T Â· m / A ) (8 . Ã— 10 22 J / T) p 1 + 3 sin 2 78 . 5 â—¦ 4 Ï€ (6 . 37 Ã— 10 6 m) 3 = 6 . 11 Ã— 10 âˆ’ 5 T , and, using the result of part (b) of problem 6, Ï† i = tan âˆ’ 1 (2 tan 78 . 5 â—¦ ) = 84 . 2 â—¦ . A plausible explanation to the discrepancy between the calculated and measured values of the Earthâ€™s magnetic Feld is that the formulas we obtained in problem 6 are based on dipole approximation, which does not accurately represent the Earthâ€™s actual magnetic Feld distribution on or near its surface. (Incidentally, the dipole approximation becomes more reliable when we calculate the Earthâ€™s magnetic Feld far from its center.)...
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This note was uploaded on 11/12/2011 for the course PHYS 2001 taught by Professor Sprunger during the Fall '08 term at LSU.
 Fall '08
 SPRUNGER
 Physics

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