What is difference between working principles of microwave oven and induction stove? Why are only stainless steel vessels preferred for the induction stove instead of copper, brass and aluminium, which are good conductors of heat?
While there is some similarity in the working of microwave oven and induction stove as both consume electric energy for heating, the similarity ends there. Working principles of microwave oven and induction stove are poles apart.
These cooking devices differ from each other in the way the heating process takes place, and the process by which the cooking utensils get heated enough to cook the food.
Working mechanism of induction stove:
- Under the ceramic plate of the induction stove, there’s a coil of metal. When you turn on the power, an alternating current flows through the coil and produces an invisible magnetic field above, below, and all around it. Unless there’s a pan on the cooking zone, no heat is produced: the cooking zone remains cold.
- Place a pan on the cooking zone and the magnetic field produced by the coil (shown here with blue lines) penetrates the iron inside it.
- The magnetic field induces whirling electrical (eddy) currents inside the pan turning the pan into a heater.
- Heat from the pan flows directly into the food or water inside it.
Note: Induction cooking only works properly with cooking pans containing iron—the only metal that efficiently produces electrical (eddy) currents and heat from magnetic fields. Copper and aluminum pans and glass cookware don’t work.
Working Mechanism of microwave oven:
In case of microwave oven, microwaves which are of low wave lengths (about 12 cm) but contain high energy, are produced through a device known as magnetron. The microwaves are reflected on to the cooking vessel where the food is stored.
The high energy microwaves vibrate the molecules of the food at very high frequency (2500,000000 per sec) which in turn produces high quantity of heat energy. The heating of food is more uniform as compared to other methods. However, only non metallic containers can be used to store food inside the oven as metallic containers are likely to reflect back the micro waves.