Answer:
a) Scales of pine closes and opens up with the variation in moisture content of air.
b) Cold sunglass meets warm moisture laden air and hence water droplet are suspended on the surface of sunglass.
Explanation:
a) Being a natural hygrometer, pine cone through its physiological activities indicate the presence of humidity in air.
The ridges of the pine consists of scales and the seed is inside it. In a humid environment, the scales absorbs moisture and swell and close the cone. This also prevents the seed from rotting due to excess moisture. With the reduction in moisture content of air, moisture in the scales of pine cone evaporates and the cone open up.
b) Sunglass gets cold since it is inside the airconditioned temperature of car. When the sunglass is placed outside the car window, moisture laden hot wind strikes the cold sunglass and it suspends its moisture there on the surface of glass as water droplets.
