Students can Download Chapter 8 Winds, Storms and Cyclones Questions and Answers, Notes Pdf, KSEEB Solutions for Class 7 Science, Karnataka State Board Solutions help you to revise complete Syllabus and score more marks in your examinations.
Karnataka State Syllabus Class 7 Science Chapter 8 Winds, Storms and Cyclones
Class 7 Science Winds, Storms and Cyclones NCERT Textbook Questions and Answers
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 cooler air comes down.
d. Air moves from a region of high pressure to a region of low pressure.
Suggest two methods to find out wind direction at a given place.
The flowing methods can be used to get the directions of wind.
- Take some fine the lighter sand in your hand and slowly step it off. Movement of dust particles in a particular direction will give the direction of wind flowing.
- Fly a Kite, the direction of the kite flies shall be the wind direction.
- Take bit of paper on your palm. The piece will fly in the direction of wind is blowing,
- Use anemometes or wind wane.
State two experiences that made you think that air exerts pressure (other than those given in the text.)
We can experience air pressure in our daily activities such as
- When we blow a balloon, the balloon becomes tight. If we try to fill more air, then the balloon bursts after an extent. This happens because air exerts pressure.
- Trees leaves and branches flutter due to pressure exerted by air in the form of wind.
You want to buy a house, would you like to buy a house having windows but no ventilators? Explain your answer.
A house having windows but no ventilators should not be bought. This is because warm air being lighter rises up and goes out of the house through, ventilators. The cool air from outside being heavier comes in through windows. If there are no ventilators, then the warm, air cannot exit and we feel suffocated.
Explain why holes are made in hanging banners and hoardings.
Air exerts pressure in all directions. If banners and hoarding do not have holes, the pressure exerted by wind may tear them off or make them fall. Holes let the air pass through and reduce the air pressure on banners and hoardings.
How will you help your neighbours in case cyclone approaches your village/town?
In case cyclone approaches, we should help our neighbours in the following ways :
- By helping them in moving to cyclone shelters and other safe places.
- By asking them to take necessary steps to shift animals, vehicles and household goods to safer places.
- By calling the emergency services such as police, fire brigade and medical centers when required.
- By not pressurising the rescue force by making undue demands.
What planning is required in advance to deal with the situation created by a cyclone?
Self – help is the best help. Therefore it is better to plan in advance and be ready with defense against any approaching cyclone. Planning required in advance to deal with cyclone-hit situations.
- Keep an emergency kit at home.
- Store enough food in waterproof bags.
- Store safe drinking water as contaminated water can cause diseases.
- Keep phone numbers of emergency services like police, hospital, friends, and relatives ready.
- Make necessary arrangements to shift the essential household goods, domestic animals and vehicles, etc to safer places.
Which one of the following places is unlikely to be affected by a cyclone.
ii. Mangaluru (Mangalore)
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 cyclones.
i. In winter the winds flow from the land to the ocean.
Class 7 Science Winds, Storms and Cyclones Additional Important Questions and Answers
How do you know that air exerts pressure? Give some examples.
Moving air exerts pressure, when the air blows we can see the fluttering of leaves in the tree, banners, and flags.
What is an anemometer?
An anemometer is an instrument which is used to measure the speed of the wind.
How monsoon around formed?
In summer, near the equator the land warms up faster and most of the time the temperature of die land is higher than that of water in the
oceans. The air over the land gets heated and rises. This causes the winds to flow from the t oceans towards the land are the monsoon winds.
How thunderstorm occurs?
Thunderstorms develop in hot, humid tropical areas like India very frequently. The rising temperature produce strong upward rising winds. These winds carry water dropletes upwards where they freeze and fall down again.
The swift movement of the falling water droplets along with the rising air create lightning and sound this thunderstorm.
How Cyclones are formed? Explain the process.
Before the cloud formation, water takes up heat from the atmosphere to change into vapour. When water vapour changes back to liquid form as raindrops, this heat is released to atmosphere. The air around warms and tends to rise and causes a drop in pressure. More air rushes to the centre of the storm. This cycle is repeated; The chain of events ends with the formation of a very low-pressure system with very high – speed winds revolving around is called Cyclone. Factors like wind speed, wind direction, temperature and humidity contribute to the development of Cyclones.
A bolt of lightning is dangerous, why?
A bolt of lightning travels at a speed of more than 400,000 km/h. It can heat the air around it to a temperature which is more than 4 times of temperature of the surface of the sun. So it is very dangerous.
II. Fill in the blanks :
- The warm air is lighter than cold air.
- The monsoon is derived from the Arabic word mausam. which means season.
- The monsoon winds carry water and it rains.
- Wind currents are generated due to uneven, heating on the earth.
- The Cyclone in American continent called a hurricane and in the Philippines and Japan a typhoon.
- A tornado is a dark funneal shaped cloud.
- Wind speed plays an important role in the formation of storms.
- The instrument that , measures the wind speed is an anemometer.
- The centre of a cyclone is calm and it is called as eye of the storm
- The advanced technologies which monitors cyclones are Satellite and radars.