DEAR SIR ,

1. when we switch off the fan the fan keeps on rotating for some time . why is it so ?

1. In India when I come for summer vacation i can see a lot of stars but here in saudi arabia I cant see the stars . its very rare . why is it so ?

Dear student,

1. When you switch off the fan, there is an inertia of the fan due to which the fan continues to move under inertia. Also since there is friction between the components of the moving parts, the fan comes to rest after some time.
2. The stars are visible depending upon which part of earth you are in and at which time of the day/night you are looking at the sky. It may be possible that whenever you are looking at the sky, the stars arent present in your visual area and may be present in some other time.