26. , R1 R2, C . . , . .
I R1 - I1 I:
I= I1+ I
, , , , :
I1R1+IR2=
q/C- I1R1=0
I I1 IC=dq/dt,
/R1,
T=R1R2C/(R1+R2). , , dq/dt=0. : qm=T /R1. ,
q (t)=qm(1-exp(-t/T))
27. , R1 R2, L . . , . .
I R1 - I1 IL:
I= I1+ IL
, , , , :
I1R1+IR2=
LdIL/dt- I1R1=0
I I1 ,
/TR2,
T=(R1+ R2)L/R1R2. , , , dIL/dt=0. : Im = /R2. ,
IL q (t)=Im(1-exp(-t/T))
28. LC .
-
.
U(t)=Umcos(w0t+j), I(t) = CdU/dt=-w0C Umsin(w0t+j)=-(Um/r)sin(w0t+j). Im=Um/r,
- .
29. - , = 1 F L = 1 , t = 1 a = 2 . .
t a = exp(bt). b = (lna)/t = R/2L, R=(2L/t)lna = (2 10-6/1 10-3) ln 2=1.4 10-3 , Q=r/R=71.4