3)
Now if the charge Q on the capacitor plates changes with time, there is a
current i = (dQ/dt), so that using Eq (8 3), we have
d
d
dd
d
d
tΦE
t
Q
tQ
=



ε =
ε
0
0
1
This implies that for consistency,
ε0
d
d
tΦE


  = i
(8 4)
This is the missing term in Ampere’s circuital law