In article ,
"MikeS" writes:

"Andrew Gabriel" wrote in message
...

Test the capacitor by connecting it in series with a 40W
lightbulb. The lamp should come on dimmer than normal. If
it doesn't come on at all, the capacitor has gone open-
circuit, and if it comes on full brightness, the capacitor
has gone short-circuit.

Gabriel,
Doesn't a capacitor conduct electricity whilst its charging when its charge
no electricity is conducted this is when it a dc current but of course if
its a/c current then it will charge and discharge to the frequency of the
a/c current.

Yes. So with AC, it continuously charges and discharges, which
means an AC current flows through it, and the lamp will light.
The current will actually be slightly out of phase with the
mains voltage waveform -- for a capacitor it will be leading
the voltage waveform. The capacitor will present an impedance
which will drop the effective voltage to the lamp (like a
resistor, but with no power loss) which is why the lamp will
be dimmer, if the capacitor is working.

--
Andrew Gabriel