6 - Plaque de cuivre plongée dans un champ magnétique

−→
E=−→ E0cos [2πf t +ϕ(M)]
−→ =γ−→
E0cos [2πf t +ϕ(M)]
−→d=ε0
∂−→ E
∂t =−2πf ε0−→
E0sin [2πf t +ϕ(M)]
−→
E0T= 1/f
α=||−→d||infty
||−→||infty
=2πf ε0||−→
E0||
γ||−→ E0|| =2πf ε0
γ
f0α= 10−3
f0= 10−3γ
2πε0
f0= 10−35,6.107
2π×1
36π.109
=⇒f0= 1015 Hz
f0
−→
rot(−→ E) = −∂−→
B
∂t
−→
rot(−→ rot−→ E) = −−→ rot Ã∂−→
B
∂t !=−∂ ∂t −→
rot(−→ B)
−→
B
−→
rot(−→ B) = µ0−→ =µ0γ−→ E
−→
rot(−→ rot−→ E) = −µ0γ∂−→
E
∂t
−→
rot(−→ rot−→ E) = −−→ grad ³div −→ E´−∆−→ Ediv(−→ E) = ρ
ε0
= 0
ρ= 0
∆−→ E−µ0γ∂−→
E
∂t =−→
0