WIND, STORMS AND CYCLONES
1. What is wind? What is the cause of wind?
A. Moving air is called wind. Air moves from high pressure region to the low pressure region. It is caused due to the difference in air pressure
between the two places. Due to the heat of the sun air becomes warm, producing a low pressure. So, the warm air rises up and the cool air from
the surrounding moves towards the area.
2. What is cyclone and how is it formed?
A. Winds blowing at a speed of 120 km per hour or above are known as cyclone. A cyclone is known by different names in different parts of the world. It is called ‘hurricane’ in the American continent. It is called typhoon in Japan, China and Philippines. In Australia, it is called Willy-Willies.
Formation of cyclone: The formation of cyclone is a very complex process. Due to heat of the atmosphere water gets evaporated and changes to water vapour. When water vapour changes back to water due to condensation, the heat is released to atmosphere and warms the air around. Then the hot air rises up causing a drop in pressure. More air from surrounding regions not only rushes in but also starts spiraling. This cycle is repeated. This chain of events ends with the formation of a very low-pressure system with very high speed winds evolving around it. This weather condition called a cyclone. Factors like wind speed, wind direction temperature and humidity contribute to the development of cyclone.
3. What are the different reasons for wind current?
A. The different reasons for wind currents are :
i) Uneven heating between the equator and the poles due to shape of earth and its inclination.
ii) Uneven heating of land and water.
4. What are monsoon winds?
A. The seasonal winds bring rain between June and September in India and South Asia are known as Monsoon winds.
There are two types of monsoon winds. They are
1. Summer Monsoon winds ( Sea breeze)
2. Winter Monsoon wind ( Land breeze)
Summer Monsoon Winds: In summer near the equator, the land become warm and the temperature of the land increases. The air above the land becomes warm and rises up. This causes the air from the ocean blow towards the land. These are known as Summer Monsoon Winds.
Winter Monsoon Winds: In winter, the direction of the wind flow gets reversed. It blows from the land to the oceans. These are known as Winter Monsoon Winds.
3. What are the advantages and disadvantages of rain?
A. The Advantages of rain are as under:
1. It provides water for agriculture.
2. It recharges the under ground water sources.
3. It helps in recharging the rivers, ponds etc.
The disadvantages of rain are as follows:
1. Excessive rain causes water from the river flow out of their bank causing flood.
4. What is Thunderstorm?
A. Thunderstorms develop in hot, humid tropical areas very frequently. The rising temperature produces strong upward rising winds. These winds carry water droplets upward. At a certain height these tiny water droplets freeze and fall down again. Because of their swift movement, the water and ice particles rub against each other and build up a negative electric charge in the cloud. The electric charge is then released by the clouds by the stroke of
lightning and thunder is produced.
5. What are the precautions in thunderstorms?
A. The precautions in thunderstorms are as below.
1. It is well advised not to take shelter under an isolated tree, because an isolated tree is prone to lightning. While in a forest, it is advised to take
shelter under a small tree.
2. Do not lie on ground.
3. Do not take shelter under an umbrella with a metallic rod, as pointed metallic materials are prone to lightning.
4. Do not sit near a window. Open garages, storage sheds, metal sheds are not safe places to take shelter.
5. If one is in water, he should get out and go inside a building.
6. A bus or car is a safe place to take shelter.
7. What are tornadoes?
A. A tornado is a dark funnel shaped cloud that reaches from the sky to the ground. The neck of the funnel sucks up anything which comes in its
way. The tornadoes may form within cyclone. The wind in a violent tornado can circle around at a speed of 300 km per hour.
8. What is eye of a storm?
A. The centre of a cyclone is a calm area. It is called the eye of the storm. The diameter of the eye varies from 10 to 30 km. It is a region free of
clouds and has light winds.
9. Steps taken by government for cyclone warning.
A. The steps taken by government for cyclone warning are as under.
1. With the help of Satellite Weather Observation Radars, the formation of cyclone, its direction and intensity is detected by the meteorological
department.
2. The news of the formation of cyclone , its direction and intensity etc is immediately telecasted and broadcasted at least 48 hours before the
arrival of the cyclone.
3. Cyclone warning is telecasted and broadcasted every hour or half hour.
10. Describe the action on the parts of the people.
A.
1. We should not ignore the warning issued by the meteorological department through television, radio or news papers.
2. We should make necessary arrangement to shift the essential household goods, domestic animals and vehicles etc to safer places.
3. Avoid driving on roads through standing water.
4. Keep ready the phone numbers of all emergency services like police, fie brigade and medical centers.
11. What are the other precautions if you are staying in a cyclone hit are?
A. The precautions in a cyclone hit area are as under.
1. Do not drink water that could be contaminated. Always store drinking water for emergency.
2. Do not touch wet switches and fallen power lines.
3. Do not go out just for the sake of fun.
4. Do not pressurize the rescue force by making undue demands.
5. Cooperate and help your neighbours and friends.
BOOK QUESTIONS
1. Fill the missing word in the blank spaces in the following statements:
(a) Wind is moving air.
(b) Winds are generated due to uneven heating on the earth.
(c) Near the earth’s surface warm air rises up whereas cold air comes down.
(d) Air moves from a region of high pressure to a region of low pressure.
2. Suggest two methods to find out wind direction at a given place.
A. Two methods to find out wind direction at a given place are:
1. An instrument called anemometer can be used to find the direction and speed of the wind.
2. Hold a strip of paper outside. The direction in which the paper is blowing is the direction of the flow of the wind.
3. State two experiences that made you think that air exerts pressure.
A Two experiences that made us think that air exerts pressure are:
1. Whiling cycling against the direction of the wind, it is difficult to ride. It shows that the air exerts pressure.
2. While rowing a sailboat in the direction of the wind, it is always easier to row and while rowing a sailboat against the direction of the wind, it is very difficult to row. It also shows that the air exerts pressure.
4. You want to buy a house. Would you like to buy a house having windows but no ventilators? Explain your answer.
A. No, I would not like to buy a house having windows but no ventilators. Warm air rises up and cool air comes downward. So, to make a stream of cool and fresh air to continuously flow to the house through the windows, there must be some ventilators in the upper part of the wall.
5. Explain why holes are made in hanging banners and hoarders.
A. Holes are made in hanging banners and hoarders to allow air to pass through them as a result of which there will be less pressure of air on the banners or hoarders. Unless it is done, these may be uprooted or distorted due to the pressure of the air.
6. How will you help your neighbours in case cyclone approaches your village/town?
I will help my neighbours in case cyclone approaches my village/town by the following ways.
I will help my neighbours in shifting their household articles, domestic animals etc to a safe place.
2. I will provide phone numbers of all emergency services like police, fie brigade and medical centers.
3. I will give them safety advice like avoiding driving on roads through standing water, not touching wet switches etc.
7. What planning is required in advance to deal with the situation created by a cyclone?
A. A good planning in advance will minimize the damages to be caused by a cyclone. Hence, the following planning is required.
1. The cyclone warning issued by the meteorological department through television, radio or news papers must not be ignored and followed
carefully.
2. The household articles, domestic animals, vehicle etc should be shifted to safe places.
3. The telephone numbers of essential services like police, fie brigade and medical centers etc should be kept ready to meet the emergency
situation.
8. Which one of the following place is unlikely to be affected by a cyclone.
a) Chennai 2. Mangaluru iii) Amritsar d) Puri
9. Which of the statements given below is correct?
i) In winter the winds flow from the land to the ocean.
ii) In summer the winds flow from the land towards the ocean
iii) A cyclone is formed by a very high-pressure system with very high-speed winds revolving around it.
iv) The coastline of India is not vulnerable to cyclone
NKD
1. What is wind? What is the cause of wind?
A. Moving air is called wind. Air moves from high pressure region to the low pressure region. It is caused due to the difference in air pressure
between the two places. Due to the heat of the sun air becomes warm, producing a low pressure. So, the warm air rises up and the cool air from
the surrounding moves towards the area.
2. What is cyclone and how is it formed?
A. Winds blowing at a speed of 120 km per hour or above are known as cyclone. A cyclone is known by different names in different parts of the world. It is called ‘hurricane’ in the American continent. It is called typhoon in Japan, China and Philippines. In Australia, it is called Willy-Willies.
Formation of cyclone: The formation of cyclone is a very complex process. Due to heat of the atmosphere water gets evaporated and changes to water vapour. When water vapour changes back to water due to condensation, the heat is released to atmosphere and warms the air around. Then the hot air rises up causing a drop in pressure. More air from surrounding regions not only rushes in but also starts spiraling. This cycle is repeated. This chain of events ends with the formation of a very low-pressure system with very high speed winds evolving around it. This weather condition called a cyclone. Factors like wind speed, wind direction temperature and humidity contribute to the development of cyclone.
3. What are the different reasons for wind current?
A. The different reasons for wind currents are :
i) Uneven heating between the equator and the poles due to shape of earth and its inclination.
ii) Uneven heating of land and water.
4. What are monsoon winds?
A. The seasonal winds bring rain between June and September in India and South Asia are known as Monsoon winds.
There are two types of monsoon winds. They are
1. Summer Monsoon winds ( Sea breeze)
2. Winter Monsoon wind ( Land breeze)
Summer Monsoon Winds: In summer near the equator, the land become warm and the temperature of the land increases. The air above the land becomes warm and rises up. This causes the air from the ocean blow towards the land. These are known as Summer Monsoon Winds.
Winter Monsoon Winds: In winter, the direction of the wind flow gets reversed. It blows from the land to the oceans. These are known as Winter Monsoon Winds.
3. What are the advantages and disadvantages of rain?
A. The Advantages of rain are as under:
1. It provides water for agriculture.
2. It recharges the under ground water sources.
3. It helps in recharging the rivers, ponds etc.
The disadvantages of rain are as follows:
1. Excessive rain causes water from the river flow out of their bank causing flood.
4. What is Thunderstorm?
A. Thunderstorms develop in hot, humid tropical areas very frequently. The rising temperature produces strong upward rising winds. These winds carry water droplets upward. At a certain height these tiny water droplets freeze and fall down again. Because of their swift movement, the water and ice particles rub against each other and build up a negative electric charge in the cloud. The electric charge is then released by the clouds by the stroke of
lightning and thunder is produced.
5. What are the precautions in thunderstorms?
A. The precautions in thunderstorms are as below.
1. It is well advised not to take shelter under an isolated tree, because an isolated tree is prone to lightning. While in a forest, it is advised to take
shelter under a small tree.
2. Do not lie on ground.
3. Do not take shelter under an umbrella with a metallic rod, as pointed metallic materials are prone to lightning.
4. Do not sit near a window. Open garages, storage sheds, metal sheds are not safe places to take shelter.
5. If one is in water, he should get out and go inside a building.
6. A bus or car is a safe place to take shelter.
7. What are tornadoes?
A. A tornado is a dark funnel shaped cloud that reaches from the sky to the ground. The neck of the funnel sucks up anything which comes in its
way. The tornadoes may form within cyclone. The wind in a violent tornado can circle around at a speed of 300 km per hour.
8. What is eye of a storm?
A. The centre of a cyclone is a calm area. It is called the eye of the storm. The diameter of the eye varies from 10 to 30 km. It is a region free of
clouds and has light winds.
9. Steps taken by government for cyclone warning.
A. The steps taken by government for cyclone warning are as under.
1. With the help of Satellite Weather Observation Radars, the formation of cyclone, its direction and intensity is detected by the meteorological
department.
2. The news of the formation of cyclone , its direction and intensity etc is immediately telecasted and broadcasted at least 48 hours before the
arrival of the cyclone.
3. Cyclone warning is telecasted and broadcasted every hour or half hour.
10. Describe the action on the parts of the people.
A.
1. We should not ignore the warning issued by the meteorological department through television, radio or news papers.
2. We should make necessary arrangement to shift the essential household goods, domestic animals and vehicles etc to safer places.
3. Avoid driving on roads through standing water.
4. Keep ready the phone numbers of all emergency services like police, fie brigade and medical centers.
11. What are the other precautions if you are staying in a cyclone hit are?
A. The precautions in a cyclone hit area are as under.
1. Do not drink water that could be contaminated. Always store drinking water for emergency.
2. Do not touch wet switches and fallen power lines.
3. Do not go out just for the sake of fun.
4. Do not pressurize the rescue force by making undue demands.
5. Cooperate and help your neighbours and friends.
BOOK QUESTIONS
1. Fill the missing word in the blank spaces in the following statements:
(a) Wind is moving air.
(b) Winds are generated due to uneven heating on the earth.
(c) Near the earth’s surface warm air rises up whereas cold air comes down.
(d) Air moves from a region of high pressure to a region of low pressure.
2. Suggest two methods to find out wind direction at a given place.
A. Two methods to find out wind direction at a given place are:
1. An instrument called anemometer can be used to find the direction and speed of the wind.
2. Hold a strip of paper outside. The direction in which the paper is blowing is the direction of the flow of the wind.
3. State two experiences that made you think that air exerts pressure.
A Two experiences that made us think that air exerts pressure are:
1. Whiling cycling against the direction of the wind, it is difficult to ride. It shows that the air exerts pressure.
2. While rowing a sailboat in the direction of the wind, it is always easier to row and while rowing a sailboat against the direction of the wind, it is very difficult to row. It also shows that the air exerts pressure.
4. You want to buy a house. Would you like to buy a house having windows but no ventilators? Explain your answer.
A. No, I would not like to buy a house having windows but no ventilators. Warm air rises up and cool air comes downward. So, to make a stream of cool and fresh air to continuously flow to the house through the windows, there must be some ventilators in the upper part of the wall.
5. Explain why holes are made in hanging banners and hoarders.
A. Holes are made in hanging banners and hoarders to allow air to pass through them as a result of which there will be less pressure of air on the banners or hoarders. Unless it is done, these may be uprooted or distorted due to the pressure of the air.
6. How will you help your neighbours in case cyclone approaches your village/town?
I will help my neighbours in case cyclone approaches my village/town by the following ways.
I will help my neighbours in shifting their household articles, domestic animals etc to a safe place.
2. I will provide phone numbers of all emergency services like police, fie brigade and medical centers.
3. I will give them safety advice like avoiding driving on roads through standing water, not touching wet switches etc.
7. What planning is required in advance to deal with the situation created by a cyclone?
A. A good planning in advance will minimize the damages to be caused by a cyclone. Hence, the following planning is required.
1. The cyclone warning issued by the meteorological department through television, radio or news papers must not be ignored and followed
carefully.
2. The household articles, domestic animals, vehicle etc should be shifted to safe places.
3. The telephone numbers of essential services like police, fie brigade and medical centers etc should be kept ready to meet the emergency
situation.
8. Which one of the following place is unlikely to be affected by a cyclone.
a) Chennai 2. Mangaluru iii) Amritsar d) Puri
9. Which of the statements given below is correct?
i) In winter the winds flow from the land to the ocean.
ii) In summer the winds flow from the land towards the ocean
iii) A cyclone is formed by a very high-pressure system with very high-speed winds revolving around it.
iv) The coastline of India is not vulnerable to cyclone
NKD