Question

what will happen if the amount of water vapour in the air increase

Answer 1

When the amount of water vapour is increase in the air IT form cloud and after sometime precipitation is started

Answer 2

If the amount of water vapor in the air increases, the relative humidityincreases, and if the amount of water vapor in the air decreases, the relative humidity decreases. However, relative humidity is dependent on airtemperature, too.