Is your microwave oven working properly?
Find out by placing 1 liter of water in it and measure the water temperature before and after 60 seconds.
This page will then calculate how much power (in Watt) the microwave is actually giving out.
Energy [Joule] = mass [kg] * cp * temperature change [°C], where cp is 4180 JK-1kg-1 for water (at 20°C).
1 Joule = 1 Watt for 1 second.