On Mar 16, 7:00*pm, "Dave Liquorice"
wrote:
As kettles are, essentially, purely resistive the power is
proportional to the applied volts. Stuff is speced with a volatge
range so the lower power coresponds with the lower voltage and vice
versa. I've never done the maths to see if the calculated resistance
is the same (within reason).

The variation probably covers resistance variation as well - it is
only a kettle.

For example of the four otherwise identical 700W heaters I have had,
the element wattage measured by plug in energy meter vary from 707W to
823W. The precise figure may be wrong, but as a resistive load there
is clearly quite a variation.

I think I remember a 600W kettle once... it might be boiled by now,
must find it!