
28-21Capacitance and Capacitance Measurements
Although the voltage assumes dierent values in time interval t
1
– t
2
, if the initial and nal voltages
ar
e
eq
ual
(e.g., v(t
1
) = v(t
2
)), then the net energy stored in the capacitor will be equal to zero. is implies
th
at
th
e
en
ergy
sto
red
in th
e
ca
pacitor
is re
turned
to th
e
ci
rcuit
du
ring
th
at
ti
me
in
terval;
th
at
is
,
th
e
ca
pacitor
tr
ansforms
th
e
en
ergy
wi
thout
di
ssipation
. e sto
red
en
ergy
in th
e
ca
pacitor
is as
sociated
wi
th
t
he
e
lectrostatic
eld
a
nd,
i
n
t
he
a
bsence
o
f
t
he
e
lectrostatic
eld,
t
he
e
nergy
w
ill
b
e
z
ero
.
Fr
om
th
e
vo
ltage–current
re
lationship
in Eq
uation
28.9, it ca
n
be se
en
th
at
a c