This preview shows page 1. Sign up to view the full content.
Homework #4, Chapters 5 and 6
1.
Within the region 1
5 cm, 0
0.3
, 0
z
2 cm, current density is
given as
J
= (200 cos
)
a
/(
+ 0.01)A/m
2
.
What total current in the
a
direction
crosses the surface:
(a)
= 0, 1
5 cm, 0
z
2 cm?
(b)
= 0.3
,
1
5
cm, and 0
z
2 cm?
(c) Calculate
J
at
= 2 cm,
= 0.15
,
z
= 1 cm.
2.
A certain current density is given as
J
= [100 cos
/(
r
2
+ 1)]
a
r
A/m
2
.
(a) How
much current flows through the spherical cap,
r
= 3, 0
/6, 0
2
?
(b)
What value would
J
av
have if the same total current were produced by a
uniform
current density
J
av
over the cap?
(c) The same total current flows through the cap,
r
= 10, 0
, 0
2
.
Find
.
3.
A conductor of circular cross section is constructed of steel (
6 x 10
6
/
.m) in
the region 0
1 mm, and copper (
= 5.8 x 10
7
/
.m), 1
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 11/07/2011 for the course HY 1010 taught by Professor Barker during the Spring '12 term at Columbia Southern University, Orange Beach.
 Spring '12
 Barker
 Electromagnet

Click to edit the document details