. .
, , , , . , , , , , , ,
-- . , .
, (1)
;
, dl ;
r , dl (. 1).
, , , , , . ,
|[ , ]| = dl.
, . 1,
r2 = R 2 + x 02,
sin q0 = ,
q0, r .
X dB X, ,
dB X = ,
(2)
(2) () . (. 2), , , . w , , d w d , ,
dB X = w× d. (3)
. 2,
r = x = R × ctg q,
dx = - R .
dB X = -m0 sin q d q.
q,
B X = - = m0 (cos q2 - cos q1), (4)
cos q1 = - , cos q2 = .
, . , 0 = 0.
(L >> R), . , , q1 p q2 = 0, , ,
|
|
B = m0w I. (5)
(m 1), .
, , . . . , .
. . . . I X, . 3. , n -, ,
= - e [ , ], (6)
.
. , , : , . , , , . , ( Y)
= uB; (7)
E = uB.
, . U Y
U Y = - Ec = - uBc. (8)
I X . 0, u, I X
I X = eu 0 S = eu 0 ac, (9)
S = .
(9) u (8),
. (10)
R X (10) . [3/A×]. , .
(10) , , , , .
. , . . . , , ,
B = . (11)