JS said the following on 08/12/2005 14:39:
Table 4H3B gives the volt drop of the cable in mV/A/m. You
should allow for a maximum of 2% drop in voltage at the far end
of your flex.

I'm not sure *why* you would want to know the resistance per se,
but you can work out the resistance from these figures.


Hi Rumble

I was hoping to measure the resistence across the live/neutral pins
of the mains plug and then deduct the resistence of the main lead
(which is approx 10m of 1.0 mm^2).

From the result I was looking to know what the cold bulb resistence
is and from that infer the wattage.

The idea is to save opening up the housing and taking the bulb out to
measure the resistence.


I would say it is unlikely that you will be able to reliably infer the
wattage of the lamp from its cold resistance using this method.

The relationship between the cold resistance and the (hot, nominal)
wattage of the lamp may well vary between different manufacturers and
will be dependant upon how old the lamp is (the filament gets thinner as
it ages).