"Dave Liquorice" wrote in message
. 1...
On Tue, 2 Sep 2003 12:09:26 +0100, Nick Finnigan wrote:

Conclusion: a microwave is just about as efficient for one
cup of tea, but slower.

Define "efficient".

(Useful work done) / (Energy input)

To make a mug of water hot enough for a decent cup of tea in our
1.24kW input (Cat E, 800W output) uwave would take 2 mins. Our kettle
(2.9kW) will boil the same amount of water in 45s (just timed it).

uwave = (1240/60) * 2 = 40W
kettle = ((2900/60)/60) * 45 = 36.25W

(Assuming you mean Whr not W)
So the calculated input energy for the kettle is within
10% of the estimated input for a 65% efficient uwave.
'just about' the same, given the likely errors.