P30_061

# P30_061 - 61(a We ﬁnd the ﬁeld by superposing the...

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Unformatted text preview: 61. (a) We ﬁnd the ﬁeld by superposing the results of two semi-inﬁnite wires (Eq. 30-9) and a semicircular arc (Eq. 30-11 with φ = π rad). The direction of B is out of the page, as can be checked by referring to Fig. 30-6(c). The magnitude of B at point a is therefore Ba = 2 µ0 i 4πR + µ0 iπ µ0 i = 4πR 2R 1 1 + π2 . With i = 10 A and R = 0.0050 m, we obtain Ba = 1.0 × 10−3 T. The direction of this ﬁeld is out of the page, as Fig. 30-6(c) makes clear. (b) The last remark in the problem statement implies that treating b as a point midway between two inﬁnite wires is a good approximation. Thus, using Eq. 30-6, Bb = 2 This ﬁeld, too, points out of the page. µ0 i 2πR = 8.0 × 10−4 T . ...
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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.

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