Examen d'électrostatique ENSA Tétouan 2018-2019

V1> V2> V3V3V1
q a
Φ = q
4π0Ω Ω = 4π 6
Φ = q
60
q
Φ = q
4π0Ω0Ω = 4π 24
Φ = q
240
O
λ
λ

~
E
dE =dE1cosα =dE1z
√z2+R2=λdl
4π0
z
3
√z2+R2
E=Rλ
20z(z2+R2)−3/2
~
E(z)
z0dE
dz = 0 z0=R
√2Emax(z=z0) =
λ√3
9R0
~
E

V=cst V =q
4π0r=cst
r=C C r =px2+y2+z2=C
x2+y2+z2=K