produced by Motion in the Electric Field.
9
magnetic force outside and inside
; hence
From (5) we have
From these equations we have
|
(6)
|
|
(7)
|
where
Let us first consider the case where
and
are both small. In this case
is large compared with
and
, very small compared with
; hence we see that
Since
approximately, and
, we have
The magnetic force outside the sphere parallel to the axis of
equals
or