When the
current
changes in a
circuit
containing
inductance,
the magnetic
linkage
changes and
induces a
voltage in
the
inductance:
dy/dt
= e = L di/dt
Note that
the induced
voltage has
a polarity
which
opposes the
rate of
change of
current.
Alternatively,
by
integration
with respect
to time:
Y =
òedt
= LI
The
inductance
L of
a circuit is
equal to the
induced
voltage
divided by
the rate of
change of
current:
L = e /
di/dt = dy/dt
/ di/dt = dy/di
Alternatively,
the
inductance
L of
a circuit is
equal to the
magnetic
linkage
divided by
the current:
L =
Y / I
Note that
the magnetic
linkage
Y
is equal to
the product
of the
number of
turns N
and the
magnetic
flux
F:
Y = NF
= LI
