Why do the blades of an electric fan continue to rotate for some time after the current is switched off?

The blades of an electric fan continue to rotate for some time even after the current is switched off due to Inertia

Inertia is the resistance of an object to any change in its velocity

The blades of fan were initially in motion, and they remain in motion for some time since they require an external force to stop them. This external force is provided by the air resistance, but it takes time to overcome the inertia of the fan.