P30_020.PDF

(68 KB) Pobierz
Chapter 30 - 30.20
20. The two small wire-segments, each of length a/ 4, shown in Fig. 30-39 nearest to point P , are labeled 1
and 8 in the figure below.
1
2
8
3
.
P
7
4
.
.
i
6
5
Let e be a unit vector pointing into the page. We use the results of problems 13 and 16 to calculate B P 1
through B P 8 :
B P 1 = B P 8 = √ 2 µ 0 i
8 π ( a/ 4) = √ 2 µ 0 i
2 πa
,
8 π (3 a/ 4) = √ 2 µ 0 i
√ 2 µ 0 i
B P 4 = B P 5 =
,
6 πa
B P 2 = B P 7 =
µ 0 i
4 π ( a/ 4) ·
3 a/ 4
[(3 a/ 4) 2 +( a/ 4) 2 ] 1 / 2 =
3 µ 0 i
√ 10 πa ,
and
µ 0 i
4 π (3 a/ 4) ·
a/ 4
[( a/ 4) 2 +(3 a/ 4) 2 ] 1 / 2 =
µ 0 i
3 √ 10 πa .
B P 3 = B P 6 =
Finally,
8
B P =
B Pn e
n =1
√ 2
2
+ √ 2
6
e
=2 µ 0 i
πa
+
3
√ 10 +
1
3 √ 10
√ 2
2
+ √ 2
6
e
=
2(4 π
×
10 − 7 T
·
m / A)(10A)
+
3
√ 10 +
1
3 √ 10
π (8 . 0
×
10 − 2 m)
=(2 . 0
×
10 − 4 T) e,
where e is a unit vector pointing into the page.
643282889.001.png

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika:

Zgłoś jeśli naruszono regulamin