I ( ) . I , , .. , . , .
2) - ( ). I=eυ ( ).
Pm=IS=eυπr2 Lm=mvr- => Pm/Lm=-eυπr2/ mvr=- eυ2πrr/2mvr=-e/2m (- Pm Lm). , , - . . , . =m+s+, .. m>>m >>, =m+. . F=evB. .. , , . F=ma(*)=e2/4πε0r2, εί=-d/dt=-SdB/dt=-πR2dB/dt=-E2πR E=rdB/2dt. .. F=eE=evdB/2dt, (*)Fdt=d(mv)=mdv mdv=erdB/2. .. v=ωR, rdω=erdB/2m => dω=ed/2m; ∆ω=-e∆B/2m- .
1) , , . :φ=q/4πε0r. , , , , .. q=Cφ. C=q/φ . , . . , , q . , q, .. , . R, , ε, φ=q/4πεε0R => q=4πεε0Rφ
[C]=
2) . 1 2. 2=L21I1. I1 2 ε12=- L21dI1/dt 1=L12I2; ε21=- L12dI2/dt. 1 2 . L12 L21 . L12=L21. , . . W12: W12=L12I1I2.
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4): ω=δ2/ρ => δ=(ωρ)1/2=(Qρ/Vt)1/2=0,101 /
V=63
t=1
Q=216
ρ=1,7*10-8 *
-?
5): eU=mv2/2 v=(2eU/m)½ B=μ0I/2πr
U= 0,5 F=evB*μ0eI(eU)½/πr(2m)½
r=1 =4,24*10-16 H
I=10 A
F-?
3) q=0,3 : F=F1+F2+F3 F1=q1q4/4πε0α2, F2==q2q4/4πε0(α(2)1/2)2,
F=F4 F3=q3q4/4πε0α2 . q1=q2=q3=q4=q,
q5-? F= q2(2)1/2/4πε0α2+q2/4πε0α22=q2(2(2)1/2+1)/8πε0α2
.. , F=F5, F5- q4 q5. F5=q4q5/4πε0(α(2)1/2/2)2=4q4q5/4πε02α2=q4q5/2πε0α2
.. q2(2(2)1/2+1)/ 8πε0α2=qq5/2πε0α2 => q5= q(2(2)1/2+1)/4=2,8*10-10
1 ) , , . : =F/q. - , , . A∞=qφ => φ=A∞/q. φ=q/4πε0α, A=q∆φ, => φ W/q. , : dA=Fdℓ=Eq0dℓ. dA=φq0-q0 (φ+dφ)=-q0dφ. E=-dφ/dℓ=-q∞dφ. , . grad φ . . (dq=0) E=0 => .
2) --. B~I. , : B=∑Bi. Idℓ - , v, α- . dB=μIdℓsinα/4πr2- --.
5) :
=0,2 T=2π/(1/4C-(R/2L)2)1/2. , R ,
U=9,07*10-3 T=2π/(LC)1/2=0,2*10-3C.
t=10-3 U=U0exp(-2t/T), Q=Tln(U1/U2)/t=0,2*10-3ln3/103=
U1/U2=3 =0,22. Q=βT=RT/2L, R=2QL/t=11,1 .
Q-? (R/2L)2≈103 1/LC≈103 =>
T=2π/(LC)1/2
4): 1)j=I/S=ε/RS=37500 A/2
ε=6 2)j=Ne/St => N=jSt/e=εSt/RSe=εt/Re=7,63*1017
R=80
S= 2 2
t=1 c
j,N-?
3) E=/2εoε, E=F/τl, /2εoε=F/τl
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=20 /2 Fl=4,5*10-7 H
τ=0,4 /
l=1
Fl-?
5)=2,2 æ=βt=R2π(LC)1/2/2L=πR(LC)1/2
l=0,1 L=μoμn2lS=μoμlSπ/4S2
S=12 .. N=l/d, n=N/l, n=1/d, n2=1/d2=π/4S
ρ=1,7*10-8 * R=ρl/S, l=Nπυ=πυ/d=l(π)1/2π2(S)1/2/2(S)1/2(π)1/2=
S=2*10-4 2 =πl(S)1/2/(S)1/2, R=(S)1/2ρlπ/(S)1/2 S
-? R= π(S)1/2 ρlπ(μoμlSπ/4S)l/(S)1/2S=(μ-?)
1) , E1, E2. 0. dl=E1xa-E2xa+<El>dl, <EB>- ∫Eldl=0 => (E2x-E1x)a=<EB>2l l→0 E1x=E2x. Ei=E1m+E1τ=> Ei=E2m+E2τ => E1τ=E2τ, E1τ Ei I, , E1 2. .. D=εε0E, D1τ / εε1=D2τ / εε2 => D1τ / D2τ = εε1/ εε2 , S , S1- S1=S2=S , . =∑qi , ∑qi=0 => =0. S1=D1nS, D1n- D n1, S2=D2nS, D2n- D n2. <Dn>S, =D1nS+D2nS+<Dn>S=0, n1→0, →0, Di=D1mn - , n1, n2 L Di , D1n=D2n ε0ε1E1n=ε0ε2E2n E1n / E2n=ε2/ε1=> , D , D .
2) : F=ℓIBsina, a- I dℓ, dF=dℓIBsina. : 4 , dF=I[dℓB]. : dF=dℓIBsina(dℓB) sin(dℓB)=1 F=ℓIB dA=Fdx => A= ℓIB∫(0,x)dx=IBℓx=ISB=I∆. ∆- , . ε .
3):
d1=10-4 3
ε1=7 .
d2=0,2*10-4 1/C=1/C1+1/C2+1/C3=2/C2+1/C1, C= ε0εS/d
ε2=2 C1= ε0εS/d1 C2= ε0εS/d2 1/C=2d2/ ε0ε2S+ d1/ ε0ε1S
S=0,02 2 =>C= ε0ε1ε2S/2d2ε1+d1ε2=5,16*10-9
-?
4): II : I: ε1=I1R1+Iε1r1
ε1=ε2=2 II: - ε1-ε2=I2R2+ Iε1r1+Iε2r2.
I :
r1=r1=0,5 I1+I2- Iε1=0 (A), Iε2-I2-I1=0 (B) => Iε2=I2
R1=50 : - ε1=I1R1+Iε2r2, - ε1-ε2=I2R2+ Iε1r1+Iε2r2, I1+I2=Iε1.
R2=15 .
I1,I2,I3-? - 2=50I1+0,5Iε2, -4=2I2+ 0,5Iε1, I1+I2=Iε1
I2=0,63A, I1=11,15A, Iε1=10,52A
5) wI=1/LC, wU=(1/LC-2β2)1/2
wU=99% wI Q=π/λ=π/β2π(LC)1/2=1/β2(LC)1/2
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w-? wU/ wI=0,99 (1/LC-2β2)1/2(LC)1/2=0,99
(1-2β2LC)1/2=0,99 2β2LC=0,0199
Q=(2/2β2LC) ½=10
1) o . q1 , q 1 2. A=-dlcosa. dlcosa=dr=> Fdr=q1qdr/4πε0r2 => A=∫dA=∫q1qdr/4πε0r2=-q1q2/4πε0r==-q1q2(1/r1-1/r2)/4πε0 => q1 q , => . A132=A14. 132=-241 =3241=0 => dA=!. q:1=F/q, dA=Rdlcosa=(E^dl); A= (Edl)=0 (Edl)- .
2) . , , . R=φ1-φ2=ε12, φ1 φ2 =-q/C ε12=-LdI/dt. IR=-q/C-dv/dt. L I=q′,dI/dt=q′, q′′+Rq′/L+q/LC=0, .. ω02=1/LC, β=-LdI/dt, q′′+2βq′+ω02q=0 . , β2<a, -ex2/4L2=1/4C. q=qme-βtcos(wt+a), w=(w02-β2)1/2 w. U=Ume-βtcos(wt+a) I=w0qme-βtcos(wt+a+ψ), sin ψ=w/(w2+β2)1/2=w/w0,cosψ=-β/ (w2+β2)1/2=-β/w0
wt*E=-∂β/∂t; divD=P; wtH=j+∂D/∂t;div B=0. . , . . -βt. λ=a(t)/a(t+T)=βT( a(t) ) Ne, , .λ=1/Ne. λ=β=R2π/2Lw= Rπ/Lw. w => λ L,C R => , .
3) -. F1+F2=0. F1=F2, .. . F1=kq1Q/x2,
q1=1,8*10-7 F2=kq2Q/(l-x)2, kq1Q/x2= kq2Q/(l-x)2 => 4x2=(0,6-x)2
q2=7,2*10-7 x=0,2
l=0,6
x-?
4): I=ε/r, I1=E/(R1+r),I2=E/(R2+r) => I1(R1+r),I2(R2+r) =>
R1=50 r=10 ε=I1/(R+r)=0,2*(50+10)=12B
I1=0,2 A
R2=110 I=12/10=1,2 A
I2=0,1 A
I-?
5): H1=I1N/π =8380 /. B H B1
=11,4 B1=1,8. μ1=B1/μ0H1=171
N=200 B2=I2Nμ0μ1μ2/(8μ0+(π -8)μ1) .. μ1=1,
I1=15A B2=I2Nμ0μ2/(8μ0+(π -8)) =>
=1 I2=22,1 A
I2-?
1) , , . p=qℓ, ℓ- . . q+=q- => E+=E-, E=-++. AMN, . -/E+=((r2+l2/4)1/2/l)E+=E-l/(r2+l2/4)1/2=ql/4πε0(r2+l2/4) (r2+l2/4)1/2, . r>>l EA=ql1/4πε0r3=P/4πε0r3- , .
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2) IS=φ( ). , . A=:d/dt. , , . :dI/dt>0, (d/dt>0), , (εsi<0) dI/dt<0, d (εsi>0). .. ~, ~I, ~I, => =LI, L- (). LR, , [L]=. , , .
H=nI, (n ). B=μμ0H=μμ0nI ψ=N (). N=nℓ. ψ=BSN=μμ0nISnℓ=μμ0n2ISℓ. L=μμ0nV => . εsi=-d/dt, =LI => εsi=-LdI/dt. In=I0e-Rt/L, Is=I0(1-e-Rt/L). τ=L/R , , .
3) ΔW=A dA=qdφ, dφ
R=1 E=τ/2πε0r dφ=-Edr A=-q∫(R,R+r)Edr ->
τ=10-5 . A=-q∫(R,R+r)τdr/2πε0r=-qτ/2πε0∫(R,R+r)dr/r=
r=4 =-qτ/2πε0ln((R+r)/R)=-9,27*10-14 = ΔW
q=3,2*10-19
ΔW-?
4) dA=I2Rdr I=Rr, R=(I2-I1)/t A=∫dA=∫I2Rdr=
R=32 =∫(0,t)(I2-I1)2rRdr/t2=)(I2-I1)2Rt3/3t2=(I2-I1)2tR/3=1280
t=5
I1=2A
I2=10A
A-?
5) η=N/ N0 P=εI=ε2/r
N0,ε,r η=(N0-ε2/r)/N0=1- ε2/rN0
η-?
1) . , : q=Ne. => , .. . . 2 . -. + . , , -, , . .. .
2), , ., . : IR=-q/C-LdI/dt L I q′, dI/dt q′′, q′′+R q′/L+q/LC, ω02=1/LC, β=R/2L, => q′′+2βq′+ω02q=0 . β2<<ω02, .. R2/4L2<1/LC q=qme-βtcos(wt+a), w=(w02-β2)1/2; w=(1/LC- R2/4L2)1/2 => w w0. x=lna(t)/a(t+τ)=βτ, a(t)- . Ne, , t e . x=1/Ne. T 2π/ω => λ=R2π/ω2L= Rπ/ωL => λ β=R/2L . T=1/ω=1/(1/LC- R2/4L2)1/2
4) II : IR+I1r1=ε1 IR+I2r2=ε2
ε1=2 I : I=I1+I2 =>
ε2=3 I=(r2ε1+r1ε2)/(Rr1+r1r2+Rr2) I=ε/(R+r),
r1=1 1/r=1/r1+1/r2 =>r=r1r2/(r1+r2) ε=(R+r1r2/(r1+r2))(r2ε1+r1ε2)/(Rr1+r1r2+Rr2)=
r2=1,5 =2,4 B r=0,6
R=20
r-?
5) I=e/T T=2πR/v S=πR2=>
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=1,6*10-19 Pm=IS=evπR2/2 πR=evR/2 L=mvR =>
m=9,1*10-31 Pm/L=evR/2nvR=e/2m=87,9*109.
Pm/L-?
1) , . . ( + - ),CH4, ( ), H2. , . 0 , ( ). . ′- , . =0+′ =0-′=0-ύ/ε0=0-pm/ε0= 0-λnε0E/ε0= 0-λnE. E+λnE =0=E+æE; 1+æ=ε, E0=εE => ε= E0/E- , , . E1=E0/ε1 E2= E0/ε2 D=εε0E (/2). : =∑qi .
2) - . , . W<0 (.. ), W=mv2/2>0. [W]>[W], . [W]>[W], , , , , . . W=0 ≠0 . =0 . , =0 W. . , , , . .. W<0, W 0 [=eU]. . W=3kT/2, , W. W= W-W => W ≈15000 . 1000-3000 . min max. . 1000-9000 . , UA, . . . , U IA=CU3/2 IA=CUA3/2 -. I , , . I , , , .
3) .. , mρ+F+F=0 mρ=F+F,
R=0,5 mρ=ρVg=ρ4πR3g/3, F=Eq
ρm=98*103/3 FA=ρmVg= ρ4πR3g/3=Eq+ρ4πR3g/3 => Eq=4πR3g(ρ-ρm)/3
E=104/ => q=4πR3g(ρ-ρm)/3E=4
ρ=8,6*103/3
q-?
4) dQ=I2Rdt, I=vt, v=(Imax-I0)/t Q=∫dQ=∫(0,1)v2Rt2dt=v2Rt3/3=
I0=0A =Imax2Rt3/t2=> Imax=(3Q/Rt)1/2=1A/c
t=10c
Q=1
R=3
v-?
1) . , . , P=βε0E, , β . , + - . . , . . , . P=∑P P=λε0E, λ ( ).
2) l, N , . , , . . ABCDA. (BCDA)BldL=μ0NI, AB CD , Bl=0; =0. DA Bl => (DA)BldL=Bl=μ0NI => =μ0NI/l=μ0NI, nm- B=μ0NI. ( , ).
3) δ′=ε0(ε-1), =q/4πε0x2 δ1′=ε0(ε-1) ==ε0(ε-1)q/4πε0h2=
h=3 =q(ε-1)/4πh2=1,5 /2
q=17*10-9 δ2′=q(ε-1)/4πr2=5,4*10-7 /2
r=5 c
ε=2 ()
δ1′, δ2′-?
4)
Rv=300 II I: ε1=I1(R1+R4)-IvRv
ε1=ε2=2,2B ε2=I2(R2+R3)-IvRv
R1=100 I I1+I2=Iv
R2=200 I1=(ε1+IvRv)/(R1+R4) I2=(ε2+IvRv)/(R2+R3)
R3=300 (ε1+IvRv)/(R1+R4)+(ε2+IvRv)/(R2+R3)=Ir => ε1(R2+R3)+
R4=400 +IvRv(R2+R3)+ε2(R1+R4)+IvRv(R1+R4)=Ir(R1+R4)(R2+R3)
Uv-? Ir=(-ε1(R2+R3)-ε2(R1+R4))/(Rv(R2+R3)+Rv(R1+R4)-(R1+R4)(R2+R3))
5) ψ=LI; ψ=N=NBS => LI=NBS => B=LI/NS=114
S=20 2 =μμ0H => μ=B/μ0H.
N=500 =0,8*103 / μ=114/4π*10-7*0,8*103=1400
L=0,29
I=5
μ-?
=0,032A Uv=IvRv=9,6B
1) . , , N=∑qi/ε0. : δ δ=q/S (/2). >> , . , . N=N+2N=ES*osπ/2+2ES*cos0=2ES. N=∑qi/ε0 => ∑qi/ε0=2E => =∑qi/∑ε0=δ/2ε0 (+) (-)
EI=EIII=0. EII=E++[E-]=2δ/2ε0= δ/ε0=> , .
2) Pm 0, . , . , > , , . λ=/T , - , , λ . =μ0NAPm2/3k, λ μ0NAPm2/3kT. , PmB<<kT. I , , , Pm I.
3) dφ=rdl/4πε0r, r ,
q=10-2 dl=rda/cosa => dφ=rda/4πε0cosa
φ-? φ=∫(a1,a2)rda/4πε0cosa .. , 1=2 φ=2r/4πε0∫(0,a1)a/cosa=2r/4πε0lntg(a/2+π/4)│(0, π/4)= 2r/4πε0lntg(π/3)=988B
4)
ε1=11 I : I2=I1+I3
ε2=14 II : ε1-ε2=I1R1+I2R2 ε3-ε2=I3R3+I2R2
ε2=16 .
R1=50 ε1-ε3=I1R1-I3R3=I1R1-I3R1-I3R3=I1R1-I3(R1+R3) =>
R2=10 I2=(ε1-ε3+I3(R1+R3))/R1, 3 I2= (ε3-ε2-I3R3)/R2 =>
R1=2 (ε1-ε3+I3(R1+R3))/R1= (ε3-ε2-I3R3)/R2 =>
I1,I2,I3-? (ε1-ε3)R2+I3R2(R1+R2)=(ε3-ε2)R1-I3R1R3 =>
I3=(R1(ε3-ε1)- (ε1-ε3)R2)/(R2(R1+R2)+R1R2)=0,242 A
I2= (ε3-ε2-I3R3)/R2 =0,152 A I1=I2-I3=-0,09A
5) 4 dB=
R=0,2 =μμ0I[dl,r]/4πr2.
r=0,3 =>
=0,20 dB Ox: dBx=dBcosa=μμ0Idlcosa/4π cosa=R/a,
I-? a=(r2+R2)1/2 ∫dB=∫ μμ0IdlR/4π ((r2+R2)1/2 )3/2= μμ0IR/4π ((r2+R2)1/2 )3/2∫(0,2πR)dl=
=μμ0IR2/2((r2+R2)1/2 )3/2 I=2B((r2+R2)1/2 )3/2/μμ0R2 μ-?
1) . , , N=∑qi/ε0. : δ δ=q/S (/2). >> , . , . N=N+2N=ES*osπ/2+2ES*cos0=2ES. N=∑qi/ε0 => ∑qi/ε0=2E => =∑qi/∑ε0=δ/2ε0 (+) (-)
EI=EIII=0. EII=E++[E-]=2δ/2ε0= δ/ε0=> , .
2) . F A=ℓIBsina, 1 F1=I1B1ℓ1 (sina=1), . F2=I2B2ℓ2 => , . B=μ0I/2πd, (ℓ1=ℓ2). F1=I1μ0I2ℓ/2πd F2=I1μ0I2ℓ/2πd => F1=F2 F=I1μ0I2ℓ/2πd - . F=I1μ0I2/2πd- , .
, F2=I1μ0I2ℓ/2πd. , I=dq/dt. 1 (), . , 2- 1 2*10-7
3) F=eE,
U=300 a=eE/m. ℓ
d=2 t=1/v, y=at2/2=eEt2/2mv2,
ℓ=10 ,
v0-? y>=d/2 => v0=ℓ(Ee/md)1/2=3,64*107 /c
4): dQ=I2Rdt, I=kt, k=(I0-I)/τ=1/2=0,5
R=12 Q=∫dQ=∫(0,τ)k2Rt2dt= k2Rt3/3=1
I0-5A
I=0
τ=10 c
Q-?
5) t→∞ Imax I=ε(1-e-(r+R)∞/L)/(R+r)=Rε/(R+r)
r=1 I=0,99Imax= ε(1-e-(r+R)t/L)/(R+r)
L=0,5 0,99 ε/(R+r)= ε(1-e-(r+R)t/L)/(R+r) e-(r+R)t/L=0,01
R=8 t(R+r)/L=ln100
τ=99% t=ln100*L/(R+r)=0,23 c
t-?
1) dA=-dW =qq1/ 4πε0r1-qq2/ 4πε0r2 =-∆W W1=qq1/ 4πε0r1 W2= qq2/ 4πε0r2 φ=W/q , . φ=q/4πε0r => A=(q1(φ2-φ1). , . φ=∞/q0, .. , ∞. , dA=-Fdl=qEdl, dA=φq0-qd(φ+dφ)=-q0dφ => Edl=-q0dφ, E=-dφ/dl=-gradφ . , . φ . .
2) : I: (L)EBdl=- ∂BndS/∂t -> ( ) II: (L)Hdl=∫(j+ j)/dS=∫(j+∂D/∂t)dS . III: DdS=∑qi D . IV: BdS=0 : .
3)
r=5 q=∫dq=τ2πr
τ=1/ dE=dq/4πε0a2=dq/4πε0(R2+r2) dEx=dEcosa, cosa=R/q
R=10 .. dEx=Rdq/(R2+r2)3/2; EA=∑dEx∫(0,q)Rdq/4πε0(R2+r2)=
-? =2πτrR/4πε0(R2+r2)=2,83 /
4) ,
ε1=1,5 ε=nε1=12*1,5=18 , =nr1=4,8
n=12 ε= ε1=1,5 , r= r1/n=0?0333
r1=0,4 I=ε/R+r -
R= 0,3 I1=18/0,3+4,8=3,53 A -
Imax-? I2=1,5/0,3+0,033=4,5 A => Imax=4,5 .
1) : 1) =0, , (φ=const0. 2) . q, , . , . , . , δ. , dS. 0, .. D =0. . Dn=0, Dn=D => DdS. δdS/δ . : DdS=δdS, .. δ=D => E=δ/ε0ε
(). . . , . => =>
2) , , . , , . 0. , + φ, , φ, .. . , . , . , , . () ε=.q. F =E′q, E′ - . =∫Fdl=∫E′ q. ε= E′ .
3) A=W1-W2
1=600 q=CU. 1/C′=1/C1+1/C2
2=1000 C′=C1C2/(C1+C2)
U=20 q= UC1C2/(C1+C2) W1=q2/2C′= (UC1C2/(C1+C2))2/2C1C2/(C1+C2)=
-? =C1C2U2/2(C1+C2)=0,075
′′=1+2 W2= q2/2C′′=(UC1C2/(C1+C2))2/2(C1+C2)=
=C1C2U2/2(C1+C2)=0,0175 =W1-W2=0,075-0,0175=0,057=57
4)
I0=10A R= RA/(n-1), n=I0/I n-1= RA/ R n= RA/ R+1
RA=0,02 I= I0/n= I0/(RA+1)=2A n=5 R= ρℓ/S =>
R=0,005 ℓ =SR/ ρ=0,0588=6
S=0,2 2
ρ=1,7*10-9 *
n=5
I,ℓ-?
5) Um=qm/C Im=ω0qm= qm/(LC)1/2
ε=8 Um=(L/C)1/2Im=2 B
L=0,02
Imax=40
Umax-?
1) . . , , N=∑qi/ε0. E=F/q, E=q/4πε0r2, - . =∑i, . , N=EnS . . N=EScos(n^E). dN=EndS- . τ=q/ℓ- . , H, r. , . N=N+2N, N=0 => N=N=EScos(n^E)=0, cos0=0 => N=ES; S=2πh => N=E2πrh .. N=∑qi/ε0, [E=∑qi/2πrhε0=τ/2πrε0] => , E=f(1/v). E.=0
2) . .
. , . 50 . 100 . . ., , . . , . . D=εε0S. D , .. ∂D/∂t>0 D. ∂D/∂t<0 ∂D/∂t D. . . I=I+I. dℓ=∑I ( ); Hdℓ=∑I( -> ) I=dq/dt=dδdS/dt, I/S=j=∫∂δ/∂t; D= εε0S; E=δ/ εε0 => D=δ ja=∂/∂t, (L)Hdℓ=∫(j+Ja)dS=∫(j+∂/∂t)dS- II . III: DdS=∑qi. IV: BdS=0. B=μμ0H, j=λE, Eqdℓ=0 EBdℓ≠0 , . Hdℓ=∑j (I- ). Hdℓ=∑I=I+I. I
3) δ1′=ε0(ε-1)E, E=q/4π ε0ε(R+x)2 => δ1′=ε0(ε-1)q/4π ε0ε(R+x)2=
R=0,05 =q(ε-1)/4π ε(R+x)2, δ1′=q(ε-1)/4π εR2,
x=0,02 δ1′=3,3*10-7/ δ2′=2,5*10-7/
ε=5
q=108
δ1′,δ2′-?
4) dq=Idt II I=kt, k=(I-I/2)/t=I/2t
I=189 I=2kt, dq=2ktdt, q=∫dq=∫(0,t)Idt=∫(0,t)2ktDt=2kt2/2=It/2
I=0 q=Ne Ne=It/2, N=It/2e=0,6*1019
t=0,03
N-?
5) n=ω/2π, => ω=2πn, ε=d.dt, εmax=Imaxρ4a/S
=0,1 =NBSsinωt, ε=NBSωcosωt: εmax=NBSω
N=100 NBSω=Imaxρ4a/S, NBa22πn=Imaxρ4a/S
=0,2 n=2Imaxρ/NBaπS=0,01 /c
S=10-6 2
ρ=0,017*10-6 *
Imax=2
n-?
3) εis=-LdI/dt=> L=μμ0N2S/ℓ [εis]= μμ0N2πd2dI/4ℓdt
ℓ=0,5 [εis]= εis/N= μμ0Nπd2dI/4ℓdt, I=[εis]/R, R=ρℓ/S, ℓ=πd
d=3 I=[εis] εis/ ρπd=μμ0NSddI/4ℓρdt=1,66
N=1500
∆I=0,2
β=17 *
k=3 2
I-?
4) => I= IA+I, UA=U=>
RA=0,16 IARA= I R, I=40A
R=0,094
IA=8A
I-?
1) , , . , 0, , , q1 , q2 ∞ q1 r12. A2=q2(0-φ2)= [q2φ2], φ1 , 2 φ2=q2/4π ε0r12,A2=q1q2/4π ε0r12. 1 : A1=q1(0-φ1)= -q1φ1, φ1=q1/4π ε0r12,A2=q1q2/4π ε0r12.=> A1=A2; W12=A1=A2=(q1φ1+q2φ2)/2. q3, ∞ r13 r23. 3 : A=A1+A3=A2+A3= q1q2/4π ε0r12+q3(q1q2/4π ε0r13+ q1q2/4π ε0r23)=4/4πε02(q1(q2/r12+q3/r13)+q2(q1/r12+q3/r13)+q3(q1/r13+q2/r23))1/2[q1φ1+q2φ2+q3φ3]=> φ1=q2/4π ε0r12+q3/4π ε0r13. , , => ∑qnφn/2, φ2- , qn, n . . ∆A=∆qU; C=∆q/U,∆q=CU => ∆H=C∆UU, A=∆Wp=∫dA=∫(0,U)CUdU=CU2/2. Wp= CU2/2=q2/2C=qU/2 . ω=W/V=εε0E2/2 , . Wp= CU2/2=q2/2C=qφ/2 .
2). , . . . . : =0, I=0, I, =0 I0≠0, I=0 ≠0. I=0 . : 0-1 , 1-2 0-4- , . Max . ( I0 ) (I0 ) - , . .. - I=f(H) , μ, . , ≠0 0. . . (0-1)- . . . . . . (1-2) (2-3) . . 3-4 . .. , , . . , t . , . , , .
1) . :+ , - . , . => . , .1) 0 =0 (φ=const). 2) =n. , . +. . , 0. . 2) , . ., . . . . , , . , , . . d/dt, d=BndS. , , , : , , , .., .. .,εi=-d/dt. , , .., -- ~,~I => ~I=>=LI. L- (). 1 , , . , , . . =nI , n . B=μμ0H= μμ0nI; Ψ=N (Ψ- ) N=nl . Ψ=BSN= μμ0nISnl=> L=μμ0n2IS= μμ0n2V
3) E 0/ε, D=ε0εE, D=Eε0+P => δ'=P=ε0 (ε-1)E0/ε=5,31 /2
0=700% ω= ε0εE2Sd/2= ε0E02Sd/2ε=9,29
ε