Class 8 Science · Original EZT practice
Pressure, Winds, Storms, and Cyclones (Class 8 Science Chapter 6): from a sharp nail to a spinning storm
The same idea that lets a nail sink into wood also drives the wind outside your window - pressure. This chapter starts with force spread over area, climbs to atmospheric pressure, and ends with how pressure differences spin up storms and cyclones. Below: the ideas in plain words, then original EZT practice with worked answers. (Note: this is original practice, not a textbook exercise key.)
10 original worked examples, 10 fresh self-check questions, with explained answers. These are not copied textbook exercises, an official chapter index or a full answer key. No affiliation with NCERT is claimed.
Official sources for topic and edition context, checked 17 October 2026:
1. Pressure = force over area
Pressure is the force acting per unit area: pressure = force / area, measured in N/m2 or pascal. The same force presses harder when the area is smaller.
2. Atmospheric pressure: the air pressing on you
Air has weight, and the column of air above every surface presses down on it. We do not usually feel atmospheric pressure because the pressure inside our bodies balances it.
3. Winds: air moving from high to low pressure
Warm air expands and rises, leaving a low-pressure region. Cooler air from nearby high-pressure regions flows in, and that moving air is wind.
4. Storms and cyclones: pressure differences gone large
Over very warm ocean water, moist air rises fast and surrounding air rushes in. The Earth rotation sets the system spinning; the eye is calm while surrounding winds are violent.
5. Staying safe in storms
During a cyclone, stay indoors away from windows, keep emergency supplies, avoid trees and electric poles, and follow official weather warnings.
Choose, solve, check, then try a fresh question.
Before calculating, read the method prompt and name the condition that makes it useful. Write your own attempt. Open the steps only when you need them, and use the check to catch a wrong sign, unit or interpretation. Finish with the fresh question before reading its answer.
Calculate pressure from force and area
Choose the method: Use pressure = force / area and keep the units with the result.
EZT practice question
A force of 100 N acts on 2 m2. What is the pressure?
Show the worked solution
- Pressure = 100 / 2.
- 100 / 2 = 50.
Answer: 50 N/m2.
Check: 50 × 2 = 100, so the original force is recovered.
Watch for this: Do not multiply force by area; pressure divides force by area.
Now try it yourself
A force of 300 N acts on 3 m2. Find the pressure.
Check your answer
100 N/m2.
300 / 3 = 100.
See how smaller area raises pressure
Choose the method: Keep force fixed and compare what happens when area becomes smaller.
EZT practice question
The same 100 N now acts on 0.5 m2. What is the pressure?
Show the worked solution
- Pressure = 100 / 0.5.
- 100 / 0.5 = 200.
Answer: 200 N/m2.
Check: 0.5 is one quarter of 2, so the pressure becomes four times 50.
Watch for this: A smaller area does not reduce pressure when force stays the same.
Now try it yourself
A force of 80 N acts on 0.4 m2. Find the pressure.
Check your answer
200 N/m2.
80 / 0.4 = 200.
Explain broad straps with pressure
Choose the method: The weight is nearly fixed; wider straps spread it over more area.
EZT practice question
Why do school bags have broad straps?
Show the worked solution
- The bag weight acts on the shoulder.
- A broad strap spreads that force over a larger area.
Answer: The pressure on the shoulder is smaller, so the strap hurts less.
Check: Pressure = force / area, so larger area gives smaller pressure for the same force.
Watch for this: The strap does not make the bag lighter; it reduces pressure.
Now try it yourself
Why are wide tyres useful on soft ground?
Check your answer
They reduce pressure on the ground.
The vehicle weight spreads over a larger area.
Explain a rubber sucker
Choose the method: Compare the air pressure inside and outside the sucker after pressing it.
EZT practice question
A rubber sucker sticks to a smooth tile when pressed. Why?
Show the worked solution
- Pressing pushes air out from under the sucker.
- Outside atmospheric pressure becomes greater than the pressure underneath.
Answer: Atmospheric pressure holds the sucker against the tile.
Check: Air leaks back under the sucker when it is pulled away.
Watch for this: The sucker is not glued to the tile.
Now try it yourself
Why does a sucker fail on a rough surface?
Check your answer
Air leaks underneath.
The inside pressure then stops staying lower than outside pressure.
Explain a collapsing can
Choose the method: Track what cooling steam does to the pressure inside the sealed can.
EZT practice question
Why does a sealed can containing steam collapse when cooled?
Show the worked solution
- Cooling condenses the steam.
- The pressure inside falls below atmospheric pressure outside.
Answer: Higher outside atmospheric pressure crushes the can.
Check: The collapse begins only after the inside pressure drops.
Watch for this: The can is not pulled inward by a vacuum; outside air pressure pushes it in.
Now try it yourself
Why does a sealed plastic bottle cave in after hot air inside cools?
Check your answer
Inside pressure falls below outside pressure.
Cooling lowers the trapped air pressure.
Find the daytime breeze direction
Choose the method: Warm air rises over the surface that heats faster; cooler air moves in from higher pressure.
EZT practice question
Land heats faster than the sea during the day. Which way does the afternoon breeze blow near a coast, and why?
Show the worked solution
- Air over land warms and rises, creating lower pressure.
- Cooler air over the sea moves toward the land.
Answer: The breeze blows from sea to land.
Check: Wind moves from higher pressure toward lower pressure.
Watch for this: Do not say the breeze starts because air is simply hot; the pressure difference drives it.
Now try it yourself
Where does air rise on a hot afternoon near a coast?
Check your answer
Over the land.
The land warms faster than the sea.
Find the night breeze direction
Choose the method: At night compare which surface stays warmer and where air rises.
EZT practice question
At night the land cools faster. What happens to the coastal breeze?
Show the worked solution
- The sea is now warmer than the land.
- Air rises over the sea and cooler land air moves toward it.
Answer: The breeze reverses and blows from land to sea.
Check: The low-pressure region is over the warmer sea at night.
Watch for this: The direction is not fixed all day; it follows the changing pressure difference.
Now try it yourself
At night, is pressure relatively lower over land or sea?
Check your answer
Over the sea.
Warmer air rises over the sea.
Explain where a cyclone gets energy
Choose the method: Follow the heat and moisture supply from warm ocean water.
EZT practice question
Why do cyclones form over warm oceans and die down over land?
Show the worked solution
- Warm water supplies heat and moisture to rising air.
- Over land, that supply is cut off and friction slows the winds.
Answer: Warm ocean water feeds the storm; land removes the supply and adds friction.
Check: Cyclones weaken after landfall even if rain continues.
Watch for this: A cyclone is not powered by cold dry air over land.
Now try it yourself
Why can a cyclone weaken after moving inland?
Check your answer
It loses warm moist ocean air.
That air supplied the storm energy.
Explain roof lift with pressure
Choose the method: Compare fast-moving air pressure above the roof with the slower air pressure inside.
EZT practice question
Strong wind can blow a roof off a house. Explain with pressure.
Show the worked solution
- Fast air above the roof creates a lower-pressure zone.
- Higher pressure inside the house pushes upward.
Answer: The pressure difference can lift the roof.
Check: The upward force points from higher pressure inside to lower pressure outside.
Watch for this: The wind does not need to grab the roof from below to lift it.
Now try it yourself
Why can a window break outward in a storm?
Check your answer
Inside pressure can exceed outside pressure.
Fast-moving outside air lowers the external pressure.
Try it yourself
Work these on paper before checking any notes. Answers are deliberately not shown here.
- A force of 300 N acts on 3 m2 - find the pressure.
- Why is it harder to walk on sand with heels than with flat sandals?
- Explain why a window can shatter outward in a storm.
- Which way does air move - high to low pressure or low to high?
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Questions about this practice page
- What is pressure?
- Force per unit area - pressure = force / area, measured in N/m2 or pascal. Smaller area means more pressure for the same force.
- Why do broad straps and wide tyres help?
- They spread the same force over a larger area, reducing pressure on your shoulder or on soft ground.
- What causes wind?
- Pressure differences. Warm air rises and leaves lower pressure, while air flows in from higher-pressure regions.
- How does a cyclone form?
- Over very warm ocean water, moist air rises and surrounding air rushes in. The Earth rotation spins the system, and warm water keeps feeding it until it reaches land.
- Are these the NCERT exercise questions for Pressure, Winds, Storms, and Cyclones?
- No. EZT pages are original practice on this chapter - use them to prepare for the textbook exercises, not as a substitute for your book.