CBSE Class 7 Science Revision Notes Chapter 8 – Winds, Storms and Cyclones
Class 7 Science Chapter 8 is an important chapter from the exam point of view as most questions are asked from it. In addition, this chapter explains important skills that are extremely useful in real-world situations. For this, Extramarks provides Class 7 Chapter 8 Science Notes on winds, storms, and cyclones.
Students can access these Class 7 Science Chapter 8 Notes from the Extramarks website. Subject matter experts write these revision notes. With the help of these notes, students can score better marks on exams.
Revision Notes for CBSE Class 7 Science Chapter 8
Access Class 7 Science Chapter 8 – Winds Storms and Cyclones Notes in 30 Minutes
CBSE Class 7 Science Chapter 8 Notes
Understanding Winds
Chapter 8 Science Class 7 Notes begins with a discussion on air pressure. Experts claim that air surrounds us constantly and applies pressure on us. The wind is characterised as the air moving naturally. Any current flowing in a specific direction is what causes this motion.
NCERT Class 7 Science Notes Chapter 8 explains that a decrease in air pressure is always accompanied by an increase in wind speed. Additionally, air tends to move from areas of high pressure to areas of low pressure.
Wind currents may result from uneven heating of the water or the land. This happens because land absorbs and releases heat more quickly than water. During summer, winds travel from cooler seas to hotter land. The monsoon season is a result of the moisture carried by these winds.
During winters, the wind blows in the opposite direction, i.e., the wind blows from the land towards the sea. The movement of the winds from the seas and oceans toward the land is what produces rain. Water is carried by these winds. After a certain point, the moisture in the clouds becomes so saturated that it pours down as rain or a mist.
Looking at Cyclones
A large mass of air can be considered a cyclone as per the standards established by the authorities. This air mass rotates violently at a height of the atmosphere of about 1015 km. Surprisingly, the eye of the storm, or the centre of the cyclone, is nothing more than a calm region.
The storm’s eye can have a diameter of 10 to 30 km. Around the storm’s eye, there is also a 150 km region of clouds. This area experience winds with speeds between 150 – 250 km/h. As the wind moves away from the centre of the cyclone, its speed will eventually decrease.
Fun Facts about Winds and Storms
It is said the uneven heating that occurs between the poles and the equator also contributes to wind currents. Let’s examine the explanation given below.
The entire process starts when the areas close to the equator experience a greater amount of solar heat. The warm air then ascends into the atmosphere. To fill its place, air from latitudes 0 to 30 degrees moves in from the north and south.
Similar to this, the air at the poles is significantly colder than the air found near latitudes of 60 degrees. In comparison, the latter is warmer. As a result, the cool air that is present around the poles will move inward to fill the space as warm air rises.
Thus, it can be said that wind currents travel from the poles to latitudes where it is warmer. This is how the uneven heating of the earth’s surface contributes to wind currents.
Benefits of Using Extramarks Class 7 Science Notes Chapter 8
Extramarks Class 7 Science Chapter 8 Notes have numerous benefits. Some of these benefits include:
- Students can review chapters efficiently in less time.
- By referring to these revision notes, students will be able to comprehend complex concepts and score better on the exams.
- Class 7 Science Chapter 8 Notes are written by subject matter experts, making them accurate and reliable.