During winter, sometimes we see a white trail at the back of a flying aeroplane in a clear sky. Explain why.

Explanation

In winter, air temperature is low.Hence, when ann aeroplane flies,the vapour released by its engine condenses and forms white clouds. If the relative humidity of theair surrounding the plane is high, we see white trail at the back of the plane for a long time before it disappears.If the relative humidity is low, the white trail is short and disappears quickly. If the relative humidity is very low, there is no formation of the white trail.