rotb≠0 - sapienza - università di roma · disegni magnetostatica author: adb created date:...
TRANSCRIPT
divB = div 1µ(4π
�
�
Idl⃗×r:r;
=µ(4π
I1divdl⃗×r:r;
�
�
divdl⃗×r:r;
= divdl⃗×r⃗r<
= divı̂ ȷ̂ kAdx dy dzxr<
yr<
zr<
=
=𝜕 dy zr< − dz
yr<
𝜕x+𝜕 dz xr< − dx
zr<
𝜕y+𝜕 dx yr< − dy
xr<
𝜕z=
= dyz − dzy𝜕 1r<𝜕x
+ dzx − dxz𝜕 1r<𝜕y
+ dxy − dyx𝜕 1r<𝜕z
=
= dyz − dzy −3xrK
+ dzx − dxz −3yrK
+ dxy − dyx −3zrK
=
= −3rK
dyzx − dzyx + dzxy − dxzy + dxyz − dyxz = 0
perchédivB = 0