NCERT Solutions Curiosity Chapter 6 .3 Formation of Wind — In-text Questions

Wind is air on the move from a region of higher pressure to a region of lower pressure. Wherever such a pressure difference appears, air begins to flow, and that flow is what we call wind.

The pressure difference is usually created by uneven heating. When one region is heated more than its surroundings, the air over it becomes warm and lighter and rises, leaving a region of low pressure behind. Air from the cooler, higher-pressure surroundings moves in horizontally to take its place. That horizontal movement is the wind we feel.

Yes — the pressure difference is the whole cause of wind, and its size decides how strong the wind is.

Activity 6.5 settles both points. Air flows from the inflated balloon to the uninflated one only while their pressures differ; the moment the pressures become equal, the flow stops and both balloons stay the same size. And as the book adds, if we could measure the speed of the escaping air we would find it higher when the pressure difference is higher.

The sea breeze and land breeze you studied in Curiosity, Grade 7, are the same effect out of doors. By day the land heats faster than the sea, so the air above the land becomes warmer and lighter, rises, and creates a low-pressure area; air from the higher-pressure region over the sea blows in as the sea breeze. At night the water stays warmer than the land, the low pressure now forms over the sea, and the wind blows from land to sea as the land breeze.