This preview shows page 1. Sign up to view the full content.
(b) When the current is at a maximum, its derivative is zero. Thus, Eq. 3035 gives
ε
L
= 0
at that instant. Stated another way, since
(
t
) and
i
(
t
) have a 90° phase difference, then
(
t
)
must be zero when
i
(
t
) =
I
. The fact that
φ
= 90° =
π
/2 rad is used in part (c).
(c) Consider Eq. 3128 with
/ 2
m
= −
. In order to satisfy this equation, we require
sin(
ω
d
t
) = –1/2. Now we note that the problem states that
is increasing
in magnitude
,
which (since it is already negative) means that it is becoming more negative. Thus,
differentiating Eq. 3128 with respect to time (and demanding the result be negative) we
This is the end of the preview. Sign up
to
access the rest of the document.
This note was uploaded on 06/03/2011 for the course PHY 2049 taught by Professor Any during the Spring '08 term at University of Florida.
 Spring '08
 Any
 Physics, Current

Click to edit the document details