a |
.
, AB, :
.
, BC,
, , , . . , ,
.
2. MN, I 1, b, I 2. MN, , , a. , , .
, MN:
, . D C MN, , , F=F1F2,
|
, a
.
dx, . , x , , Bn =-B.
x :
.
3. R =10 (B = 50 ). I = 10 . F, , .
dl . Idl .
, , . dF
,
i j (); dFx dFy dF Ox Oy.
F, , :
L , L. .
|
|
. (1)
, dFy = dFcosα, dF (). (), . dl R α,
.
.
(1) π/2 +π/2 ( ):
.
, Oy ( ). :
, ():
[ I ][ B ][ R ]=1 1 1 = 1 1 1 1 /(1 (1 )2)=1 .
: F = 2105010-30,1 = 0,1 .
4. , n= 5×103 , , N =50 S = 4 2. , . , , j = 60. O- , , , k = 6×105 · / .
- , : M=M.
, .
:
, , ,
, ,
,
5. , - .
|
-e |
R |
.
.
, ,
,
S=πR2 , , .
S ,
, (2):
:
6. = 10 , 1 h = 6 . υ.
a |
R |
- . , - . , : .
|
|
.
-
:
υ, , :
. , , h, .. ,
,
:
.
7. , I = 50 , , l = 65 , . , ?
S
.
. Bn=B. B, ,
I |
l |
x |
dx |
a |
a |
B S * |
dS=ldxx |
- , ,
d=()dS.
l, dx dS=ldx (. .). , ( x) .
.
x1 = a x2 = 2 a,
.
,
.
, ():
[ μ0 ][ I ][ l ] = 1 / 1 1 = 1 .
, = 4,5 .
8. = 10 , I = 100, - = 1 . , , 90˚.
a |
a |
I |
,
; α ( - ) .
, .. = 0, (α =0). , . α, .
dA= Mdα = IBa2sin α dα.
, :
. (1)
,
= 10010,12 =1 .
:
1) , :
1 , , 2 , .
, 1=S, 2=0. ,
= IBS = IBa2,
(1).
2) .
|
|
=ΔW = W2 - W1,
m= Ia2, cosα1 =1 cosα2 =0,
A=IBa2,
(1)