The chapter Winds, Storms and Cyclones explains how air pressure, temperature differences, and wind movement are connected. Air exerts pressure, and moving air is called wind. High-speed winds create areas of low pressure, while air naturally moves from regions of high pressure to low pressure. Students learn through experiments that air expands when heated, becomes lighter, and rises upward, creating convection currents.
The chapter describes how uneven heating of the Earth by the Sun generates wind currents. Regions near the equator receive more heat than the poles, causing large-scale air circulation. Similarly, land and water heat at different rates, producing seasonal winds known as monsoon winds. These winds carry moisture from oceans and are responsible for rainfall in many regions, especially India.
Students learn about thunderstorms and cyclones. Thunderstorms form in hot and humid conditions when rapidly rising warm air carries water droplets upward. Under certain conditions, thunderstorms can develop into cyclones. A cyclone is a powerful low-pressure system with high-speed rotating winds. The calm central part of a cyclone is called the eye of the storm, while strong winds and heavy rainfall occur around it. Factors such as temperature, humidity, wind direction, and wind speed influence cyclone formation.
G7
Science
General Concept
Thinking Skills
Logical Reasoning
Problem-Solving