QI. State whether the following statements are True or False. Correct the statements if incorrect.
1. Cold air is heavier than warm air.
2. Wind speed plays an important role in the formations of storms.
3. Thunderstorms develop in colder regions.
4. Reduced air pressure and high winds cause hurricane.
5. Air contracts on heating .
1. True 2. True
3. False – thunderstorms develop in hot, humid tropical regions.
4. True 5. False – air expands on heating .
QII. Name the following :
1. The instrument that measures wind speed .
2. The centre of a cyclone .
Ans: Eye of the storm .
3. The moving air .
Ans: Wind .
QIII. Answer the following questions :
1. What is Tornado?
Ans: Tornado is a dark funnel shaped cloud that reaches from the sky to the ground.
2. Name the factor responsible for the increase of speed of wind or cyclones .
Ans: Factors like wind speed, wind direction, temperature and humidity contribute to the development of cyclone.
3. Give few precautions that should be taken during thunder storm .
i) Do not take shelter under isolated tree .
ii) A car or a bus is a safe place to take shelter.
iii) Do not sit near a window.
iv) Do not lie on the ground.
4. What will happen if high – speed winds blew over the roofs of buildings?
Ans: If the roofs of the buildings are weak, they could be lifted and blown away due to the temperature difference created.
5. What gives rise to monsoon winds?
Ans: In summer, the air over the land gets heated and rises. This causes the winds to flow from the oceans towards land giving rise to monsoon winds.