Q48. High speed winds are accompanied by reduced air pressure. Prove the statement with help of an experiment.


Q49. Explain with the help of an activity that an increase in the speed of air, results in the drop of pressure.


Q50. Write an experiment to show that on heating the air expands and occupies more space.


Q51. How technologies help people to be protected from cyclone?


Q52. What are characteristics of Tornadoes?


Q53. Write a note on structure of a cyclone.


Q54. Take a boiling tube. Stretch a balloon tightly over the neck of the tube. You can use a tape to make it tight. Pour some hot water in a beaker. Insert the boiling tube with the balloon in the hot water. Observe for 2–3 minutes for any change in shape of the balloon. Take the tube out, let it cool down to the room temperature. Take some ice-cold water in another beaker and place the tube with the balloon in cold water for 2–3 minutes. Observe the change in the shape of the balloon. Think and try to answer:

                        i.        What makes the balloon inflated when the boiling tube is placed in hot water?

                       ii.        Why is the same balloon deflated when the tube is kept in cold water?

                      iii.        Can we infer from the first observation that air expands on heating?

                      iv.        Can you now state what happens to the air in the boiling tube when it cools down?


Last modified: Sunday, 6 January 2019, 5:23 PM