two coils are placed at a distance. Current is passed through one coil and a magnetic field is generated.
Now, if the second coil is present within the magnetic field of the first coil a magnetic field will be generated in the second coil too. If
however the second coil is outside the range of the first coil no magnetic field will be produced and so no power will be transmitted.
This method is used to charge electric toothbrushes.