What energy transformation in rice cooker?

1. Electrical Energy to Thermal Energy: The rice cooker's heating element converts electrical energy into heat. This heat is used to cook the rice.

2. Thermal Energy to Mechanical Energy: The heat from the heating element causes the water to boil, creating steam. This steam pressure can be used to move a valve or other mechanisms, depending on the rice cooker's design.

3. Thermal Energy to Chemical Energy: The heat from the heating element causes the starch molecules in the rice to gelatinize, resulting in a change in their chemical structure and making the rice soft and edible.

Overall, the primary energy transformation in a rice cooker is from electrical energy to thermal energy, with a secondary transformation from thermal energy to mechanical energy in some models.