>> . 10-11 .

2.

 


2.10.

(2.4.3), (2.4.6), (2.5.1) (2.5.2) .

(2.7.1)(2.7.7). . Q = I2RΔt , . .

, , , , , (2.8.3)(2.8.15).

, , . , , . , . , . , .

, . (. 9).

1

( = 20 ) (ε = 3,3) , . d = 2,5 . U = 100 . , , υ = 0,5 /?

. , (2.2.3), :

Δq Δt .

ε0 = 8,85 10-12 / .

,

2

ρ = 4 10-4 . I , U = 6 ? l = 20 , d = 2 .

. (2.4.3) ,

3

α1 α2 0 R01 R02. , , : ) ; ) ?

. (2.5.1) t :

R1 = R01(1 + α1t),

R2 = R02(1 + α2t)

) , (2.8.6),

R = R1 + R2 = R01 + R02 + (α1R01 + α2R02)t

, :

R = R0(1 + α't),

R0 = R01 + R02, α' .

) , (2.8.13),

0 . , , , :

4

R = 250 . , = 25 β = 4% ?

.

P = IU,                     (2.10.1)

I , a U .

P = βP = βIU.                     (2.10.2)

,

P = I2R.                     (2.10.3)

(2.10.2) (2.10.3) :

(2.10.1), :

5

1 = 50 , 2 = 25 3 = 50 , U = 110 , , 2.30, U1 = 2U = 220 . , .

. , (2.7.7), :

( ):

,

( )

P'1 1, (2.7.6):

2 3 :

, 2 3:

6

, 2.31, R1 = 2 , R2 = 5 , R3 = 2 , R4 = 40 , R5 = 10 . R4 I4 = 0,5 . .

. , 2.31 (. 2.32).

. . R5. 45, R5:

U = I1R1 + I2R2 = 7,5 2 + 5 5 = 40 .

, I1 = 7, 5 ; I2 = 5 ; I3 = 2,5 ; I5 = 2 A; U = 40 .

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