No, with sufficient load current, the choke current never goes to zero.
See the formula for the minimum choke inductance versus supply voltage
and current...the usual formula also assumes 60Hz---120Hz ripple.
Remember: V=L*di/dt. The output DC voltage is the average of the
input voltage to the choke, less any I*R drop in the choke. It MUST
be, or the current in the choke would change until it was. So the
output voltage is (nominally) 0.9* the RMS input voltage, or
0.9/sqrt(2) times the peak voltage, assuming the choke input voltage
tracks the full-wave rectified sine (in other words, the absolute value
of the sine). When the input voltage to the choke is the output
voltage, the choke current increases. When it is less, the choke
current decreases. The average choke current must be the average load
current, or electrons would accumulate somewhere. If the inductance is
large enough, and the cycles come fast enough, then the change in
current is less than enough to make the current go to zero.

It's a bit of calculating to do it for a sine wave. Just think of this
example: a square wave that sits at zero for one second, then at 2
volts for one second, then repeats. Feed it to a choke, say 2 henries.
Output of the choke to a mongo capacitor, so the output voltage
doesn't change significantly. Put a 1 amp load current on it. The
output voltage must be one volt, since that's the average of the input.
So half the time the choke has one volt across it in one direction,
and half the time it has one volt in the other direction. One volt
divided by two henries is half an amp per second. Since the average
current is one amp, the current must swing between 0.75 amps and 1.25
amps. It never goes to zero, or even close. But drop the load current
to 0.25 amps, and the choke current goes just to zero when the input is
at the end of the low period. A bit lower load current, and the choke
current would go negative (or to zero if there's a diode keeping it
going one direction only). That's why a choke input filter looses its
good regulation if the load current gets too small.

In the full wave rectifier, the choke current (if it doesn't drop to
zero) will force the diode output voltage to be one diode drop below
ground, PLUS the I*R drop in the transformer winding, when the voltage
across the outside of the secondary is zero. At that point, both
diodes will be conducting equally, assuming they are matched, and half
the choke current will come from each half of the transformer
secondary.

Hope that helps!

Cheers,
Tom
(off to Holden for a week...no internet there, so you're in John's
capable hands on this one!)

To illustrate this wi