exercices - CPGE du Lycée Montesquieu

λ~ f=−λ~v
λ
i(t)
C
R
K
I0
I0
udu
dt t= 0+
u

u(t)
¨u+ 2σω0˙u+ω2
0u=A
σ ω0A σ
T τ ω0σ
u(t)
¨s+ω0
Q˙s+ω2
0s= 0.
ω
τ
Q ω ω0
u(t)i(t)
E
t= 0+L
Q=1
R√LC
ω0=1
√LC
i(t) = exp−t/τ (Acos(ωt) + Bsin(ωt))
ω=ω0r1−1
4Q2τ=2Q ω0
ω ω0

C
δ=1
Nln i(t) i(t+NT )
T N δ =π
Q
R
ω0
x(t)ω0
t= 0 x=x0v= 0 x(t)v(t)

C
q
i(t)
q0t= 0
q(t)
e(t) = ±E u(t)
r= 50 Ω
C0= 18 pF R0= 1,0MΩ
R= 1 kΩC= 100
R= 1 kΩC= 10
R= 50 Ω C= 100
R= 1 MΩC= 100
e(t) = E e(t) =
−E

u(t)
u(t)
k m x(t)
ω0
F(t) = F0cos(ωt)
x(t= 0) = 0 ˙x(t= 0) = 0
x(t)ω= 1,1ω0
h
i(t)
C
R
η(t) = η0cos(ωt)
i(t)
i(t)
I i(t)
I ω0
∆ω Q0=ω0
∆ω
i(t)η(t)