安培环路定律
安培环路定律
§11-4安培环路定律 问题: Edi=o 1B.d=? 1.圆形环路 \I B B di=f,B dl cosO =B.2r=112r=n
E = lB .dl= ? l .dl 0 §11-4 安培环路定律 问题： =B .2π r l B.dl lB dl cos0 0 = B I l r 1. 圆形环路 π π 2 r I = 2 r μ o =μ oI
2.平面内环路 rdo=dl cose B Ⅰd9 2 dl 乐,B.dl=,Boa1=51Brd =1rd9-n1∫ma
2. 平面内环路 =μ o I 2π r I = rd μ o j r dj = dl cosθ = 2 I π μ o r B l B.dl = cosθ dl l B = l B r dj I 2π = d μ o j 2π 0 . θ r B dl I dj P O l
3.若改变积分绕行方向 doe P di B di=f,B cosadz=f, B cost 0)du B cose dl=-[at Hol 0 2r do =-1CI
3. 若改变积分绕行方向 = cos θ dl l B (π ) = cosθ dl l B I 2π = d μ o j 2π 0 = μ o I l B.dl = cos dl l B a . r B dl I dj P O l θ a θ
4.任意环路 ∵B⊥dl dldi B 1B.dl=o Bdi=,B. di,+ du) ,B du/+f,Bdi=0+uoI
B dl dl l . = + l B. l B.dl ( dl + ) = l B. dl 4. 任意环路 = 0 +μ o I dl I dl dl B ∵ B dl B dl l ∴ . = 0