[ELI5] How does a rice cooker “know” the timing to switch from cook to warm when there’s no more water in it?

Question

[ELI5] How does a rice cooker “know” the timing to switch from cook to warm when there’s no more water in it?

In: 825

Answer 1

Most of them use a super convenient property of magnets/magnetism, they tend to lose strength as temperature rises. So you just find a magnet that loses exactly the correct amount of strength at say 213° to release a switch and it will instantly cut off once all the water has boiled away.