NCERT Solutions Exploring Society: India and Beyond Chapter 3 a) Cyclones — In-text Questions
Book page 59 Updated on2026-09-05
Q1.
How are cyclones formed?
Answer
A cyclone begins as a low-pressure system over the sea and grows when that low pressure becomes intense and the winds become fast.
The structure described on page 59 and photographed in Figs. 3.13 and 3.14 — a ring of cloud spiralling in, with a clear centre.
Step by step, in the chapter's own order:
In some special situations the atmospheric pressure near the sea becomes lower than in the surrounding areas, creating a low-pressure system.
This is “an invitation to the air from surrounding areas to come into the low-pressure area”. Air from the sea moves in, bringing with it moisture and rain.
When the low-pressure system is intense and the wind speeds are high, this may result in a cyclone.
As the winds collect moisture they form clouds and rotate inwards towards the centre of the depression.
That centre is cloudless, and is called ‘the eye of the cyclone’ (Fig. 3.14).
Where and what it does. Every year the Indian coastline — especially the eastern coast — witnesses several cyclones. The destructive ones cause loss of human and animal life, damage property and infrastructure, uproot trees and cause soil erosion. The India Meteorological Department (IMD) keeps track of coming cyclones and provides information on their formation, evolution and place of landing.
Why the eye is calm: the air spiralling inwards rises in the ring of cloud around the centre. In the very middle, air sinks gently instead — and sinking air does not form cloud. So the most violent storm on Earth has a patch of quiet blue sky at its heart. It is also the most dangerous moment for anyone on the ground: when the eye passes over, people think the storm is finished, and step outside just before the far wall of wind arrives.