p p qp 1 2 (p.1.11) p q p p
1.
d l F
α
. 2
. 1.11
2 2 2 2
A = ò dA = ò(F d l)= ò Fcosα d l = ò qqp cosα /(4pee0r2) d l.
1 1 1 1
d l cosα = dr,
r2 qqp dr qqp 1 1
A = ò ------- = ------------ (---- - ---). (1.43)
r1 4pee0r2 4pee0 r1 r2
p qp p p L, p p :
A = 0
A = ò Fd l = ò qpEd l = 0.
L L
p qp = 1,
ò Ed l = 0. (1.44)
L
p p p p p . ,p- p p p . , , .
p p p, qp :
A = Wp1 - Wp2.
p (1.43)
qqp qqp
Wp1 - Wp2 = ----------- - -----------. (1.45)
4pee0 r1 4pee0 r2
p , p p p qp p q
qqp
Wp = -----------. (1.46)
4pee0r
p , p
Wp/qp = q/(4pee0r) = const.
, p Wp/qp, .
φ = Wp/qp (1.47)
p (1.47) , p q, p p p p (x, y, z)
q q
φ = --------- = -----------¾¾¾¾Ø. (1.48)
4pee0r 4pee0Ö [1] x2+ y2+ z2 )
(), p (B). 1 = 1.1. , - (). - , φ1 - φ 2 1 , ..
1 = 1,6 10-19 1 = 1,6 10-19 .
p , p, p p
n 1 n
φ = S φi = -------- S qi/ri. (1.49)
i =1 4pee0 i =1
E = - grad φ, (1.50)
grad - :
grad = i ∂φ∕∂x + j ∂φ ∕∂y + k ∂ φ ∕ ∂z. (1.51)
i, j, k - .
,
E = - dφ ∕ dr. (1.52)
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, p x1 x2
2 2
φ1 - φ2 = ò Edx = (σ / 2ee0)x│ = σ(x2-x1) / (2ee0). (1.53)
1 1
, p p d, p
d
φ1 - φ 2 = ò Edx = σ d /(ee0). (1.54)
0
, p r1 r2 p ()
r2 τ r2 τ
φ1 - φ2 = ò Edr = ---------- ò dr = -------- ln (r2/ r1). (1.55)
r1 2πee0 r r1 2πee0
R
q
φ1 - φ2 = --------(1/r1 -1/r2), r1> R, r2> R. (1.56)
4πee0
φ = q /(4 πee0R). (1.57)
R (r1 > R, r2 > R) (1.56), (r1 < R, r2 < R)
φ1 - φ2 = (q /8 πee0 R3) (r22 - r12). (1.58)
pp. p p p p p (p, ), p r1, p p p p r2.
. pp p - , p p. p . p p p p, .
= q(j2 - j1) = mv2/2,
m - p, q - p, j2 j1 - , p, p p p, .
p p j = q/4pee0 r,
mv 2/2 = q(q/4pee0r2 - q/4pee0r1),
p
¾¾¾¾¾¾¾¾Ø
/ 2q 2
v = / ---------------------
Ö 4pee0m (r1 - r2).
pp 7. p pp p τ, p p q p 1 2 p p p.
. p p p p p
2 j2
A12 = ∫d = ∫qdj,
1 j1
φ1 φ2 - , 1 2 . p φ,
dφ = -Edr.
p pp p p (1.42),
d φ = - τ dr/2 πee0r.
p
r2 q τ dr q ln(r1/r2)
A12 = -∫ --------- = --------------.
r1 2πee0r 2πee0
1.8. p. p
p, . p, p p, p (p )
C = q/j, (1.59)
q - p p, j - .
p p (). 1 =
1 /1. p - , p p:
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1 = 10-3 , 1 = 10-6 , 1 = 10-9 ,. 1 = 10-12 .
, p p p, p. p p p , S , p p d, p p p e. p p p q, p
s = q/ S. (1.60)