Question

have you seen vapour trail produced by a high flying aeroplane what can be possible explanation for this

Answer 1

The fuel that is being combusted is producing large amounts of water vapour and carbondioxide at a very high temperature.
Thus when these products are getting evolved they produce a miraj like vapour effect.

Answer 2

The possible reason for this can be that planes fly at high altitude has a low temperature and the water vapour and carbon dioxide are at high temperature , so it forms clouds that seem like lines and are known as vapour trail.