An induction cooker heats the cooking pan using electromagnetic induction, rather than heating the pan with a flame.
How it works
Electricity flows through a coil
Under the glass surface is a coil of copper wire.
The cooker sends alternating current (AC) through this coil.
A changing magnetic field is produced
The AC creates a rapidly changing magnetic field above the coil.
The magnetic field enters the pan
If you place a suitable metal pan on the cooker, the changing magnetic field induces eddy currents inside the bottom of the pan.
The pan gets hot
The pan has electrical resistance.
The eddy currents flowing through that resistance produce heat.
That heat then cooks your food.
So the basic idea is:
AC electricity → copper coil → changing magnetic field → eddy currents in pan → heat
Although eddy currents are induced in the pan, they do not cause an electric shock because the current flows in a closed path within the pan. The electrical resistance of the pan causes these currents to generate heat. In an induction cooker, eddy currents are deliberately induced in the pan to produce heat.
That's why an induction cooker needs a magnetic/induction-compatible pan, such as many iron or magnetic stainless-steel pans.