(Jack Ferman) wrote in
:




On the other hand, I once accidently put a ceramic dinner plate that
had a decorative gold rim into the microwave. The sparking was
impressive and the grub on the plate never warmed up at all. I expect
the mobility of the gold rims electrons sucked up all the microwave
energy. Someone else told me that was a good way to burn out a
microwave.

A loop of metal in an RF field tends to look like a short circuit.
Try it with loosely crumpled aluminum foil. (Actually, don't!)
Food seems to be innately higher impedance, and the mass is greater
than a thin gold foil so heating is much slower, and less
spectacular. It's not nuclear physics, just basic RF electronics.

Do not induction furnaces operate at much lower frequencies.

I think so, but probably still in the RF range.

--Damon