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Question
A coil of 200 turns carries a current of 4 A. If the magnetic flux through the coil is 6 x 10-5 Wb, find the magnetic energy stored in the medium surrounding the coil.
Solution
Given data:
N = 200 turns
i = 4A
ΦB = 6 × 10-5 Wb
Magnetic energy UB = ?
`"U"_"B" = 1/2 "Li"^2`
`therefore "U"_"B" = 1/2 ("N"phi_"B")/"i" "i"^2`
`"U"_"B" = 1/2 "N"phi_"B" "i"`
`= 1/2 xx 200 xx 6 xx 10 xx 4`
UB = 24 × 10-5 J
UB = 0.024 J
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