1. ( )
dH = (I sin α dl)/(4πr2 ),
dH , dl, I, ; α - dl; r Idl .
2. ( )
H = I/(2R),
R .
3. , ( )
H = I/(2πa),
, , .
4. ( )
H = (R2I)/2(R2+a2)3/2,
R ; , , .
5.
H = I n,
n ().
6.
H = I n (cos α1 cos α2) /2,
α1 α2 -, .
7.
= μ0 μ ,
μ ; μ0 = 4π × 10-7 / .
8.
F = I l sin a,
F , ; I ; B ; l ; a .
9.
L
F = (μ0 μ I1 I2 L)/(2π d),
L ; d .
10.
F = q B V sin a,
F , , V; q ; ; a .
11. ( ) = const
= B S cos a,
; S , ; a .
12.
dA = I d,
d , .
13.
<ε> = -D/Dt,
ε , ; D ; Dt , .
14.
<ε> = -L (DI/Dt),
L ( ); DI , Dt.
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15.
L = μ0 μ n2 l S,
n l; S .
16.
W = L I2/2,
L ; I .
w= B2/20 =BH/2,
B ; .
17.
,
L ; C ; R .
( )
18. R ≠ 0
(δ = R/2L) .
δ = 0, :
U = U0 cos ωt.
19.
I = U/Z,
I U , I0 U0 :
Z .
R, L, ,
20.
P = I U cos φ,
j .
1. , , 10 . , R = 10 , α = 60○.
. , . , , , I ( (1)), L R, I ( (2)).
(1)
(2)
; φ1 φ2 , -, .
(3)
. α = 60○, 1/6 , . . L = 2πR/6=πR/3. (2),
(4)
(1) . , , , φ1= 30○, φ2= 90○. = = R sin φ = R/2. , φ1, φ2 (1),
(5)
, , (1).
(6)
dl , ( ) - , , π. , sin(dl,r) = 0. (6) . , dB = 0 . , . (3) :
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(7)
, , , , , . , , , . ( ) , (7)
=
, (4) (5),
, : I = 10 A, R = 0.1 , μ0 = 4π × 107 /, , = 6,9 .
2. I1 = I2 = I =10 . = 0.3 . , 1=0.15 , 2 = 0.2 .
. , :
, , , , . , . α.
(1)
1 2 , I:
, (2)
φ1, φ2 , -, , .
, , , . φ1= 0, φ2 = π.
(3)
cos α, (1), , , , . , , , , . I1 , I2 . , , .
1, 2 β. , ,
α + β = π (4)
(5)
(4) (5)
(6)
(1) 1, 2, o (3), cos α (6),
( ) , :
.
3. 10 × 102 bc, ad 0,1 25 / . , bcd.
. , , ( ).
1. d , , ,
(1)
. , L, x.
S
= S = BLx.
(1) , , L ,
dx/dt = V c ad.
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(2)
B, L, V, :
ε = 25 .
(2) , , (. . ). , .
2. ,
, (3)
q .
ad V (). , . ,
F = qVB.
ad L, , (3),
(3),
(4)
( ) (2).
4. 0.1 , ,
0.65 × 105 × . 2 . . .
. ,
(1)
pm ; B ;
α .
, sin α = 1
pm = I × S,
S = π·R2 , (1)
M = μ·μ0·ISH. (2)
(3)
(3) ,
/.
5. , , 50 , , 0.08 . .
. : , , , , . , ,
L ,
, ,
.
,
.
6. , , 900 /, 36.5 , 39.85 /.
.
.
α = 90○,
.
μ = 1 ( ); μ0= 4π × 107 /.
:
.
7. , 100 2 1000 , 10 . .
.
ε , ; S ; d .
.
, :
|
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L .
T , λ, .
λ =cT,
.
T = λ / .
T C, C d,
:
S = 100 2 = 102 2;
L = 1000 =1000 × 109 ;
c = 3 × 108 /;
λ = 10 ;
ε = 1;
/.
d,
.
8. 110 5·105 , 200 4 .
:
) , 100 ;
) , ;
) .
. ) , , ,
(1)
U ; ; R ; ; ω = 2πν ; ωL ;
.
(1) ,
.
) :
(2)
(2) L C,
.
) , , . .
,
.
UL UC ,
.