Why does an electric fan continue to rotate for some time even after the fan is switched off?

An electric fan continues to rotate after being switched off due to inertia. Inertia is the tendency of an object to resist changes in its state of motion. When the power is turned off, the fan blades still have momentum and will continue to rotate until the friction and air resistance slow them down and eventually stop them. The duration of the rotation depends on factors such as the fan's speed, blade design, and the materials used.