When we remove the pan, the circuit will be shorted, right? Why it don't damage the cooker? Even if we use something like an MCB, it should trip something and someone needs to turn it on. Then how is it done?
Your induction cook top can sense when the pot is on top of it and switch itself ON or OFF as the case may be. The current through the coil is being constantly measured and when it senses the pot being taken away it reduces the current. So you can turn on an inductive cook without a pan on it and do no damage.