I just made popcorn in the microwave and I wonder how much energy my popcorn absorbed and how much energy was consumed by oven. It was 90g of corn and butter (kind of...) and it needed 800W for 3 minutes (800W * 3/60h = 40Wh).
I guess if the popcorn with some fat had absorbed all this energy it would have reached its flash point. So I'm assuming that the popcorn only absorbed some of the microwave energy.
How efficient are microwave ovens? I mean the approximate percentage efficiency.
Does the magnetron (or whole oven) draw significantly less energy when there is little (microwave-absorbing) food in the microwave?
I can't check it myself because my microwave oven is built into the furniture along with other appliances and I don't have access to the socket.
Here is similar question:
Efficiency of the microwave oven
but it does not answer my question about "approximate efficiency in percent".