22. - , a . m. .
b - . :
B0cosa=Bcosb
:
B0sina=(B/m)sinb
tgb=mtga
,
.
23. N=500 , I= 1A. r=1 , R=10 . L=1 . , . m=1000, . .
H1 - , - H . ,
2pRH1+HL=NI
, .
mH1=H
H1=NI/(2pR+mL), B1=B=mm0 NI/(2pR+mL).
J=B1 -m0H1=(m-1)m0 NI/(2pR+mL)
w1=BH1/2, w=BH/2. Vc=pr22pR, V=pr2 L.
W= w1 Vc +wV=(1/2) pr2mm0 (NI)2/(2pR+mL)
.
24. . L=10 m=20 . B=0.1 , . ? R=0.05 , , g=9.8 /2.
v, dt , , , dS=Lvdt. dF=BLvdt, ,
= BLv,
I=/R=BLv/R. F=BLI=(BL)2v/R. , .. . , .
, :
|
|
v=mgR/(BL)2
, v =0.02 9.8 0.05/(0.1 0.1)2 = 98 /
25. R L, . n. , , I. : R=1 , l=50 , n=15 /, I=1 .
B= m0nI, B =0, H= nI. F1=BS=pR2 m0nI. N=nl . F=F1N=m0p R2ln2I=LI. , L=m0p R2ln2. W = LI2/2=m0p R2ln2 I2/2. V=p R2l, w = W/V=m0n2 I2/2=BH/2
:
w = ,
, .