Pressure, Winds, Storms, and Cyclones explains how force, area and air pressure shape weather events.
These NCERT Solutions help students answer Chapter 6 questions on liquid pressure, wind, lightning, storms and cyclones.
A school bag with narrow straps hurts more than one with broad straps. Water from an overhead tank flows faster when the tank is placed higher. Balloons move closer when fast air is blown between them. Chapter 6 uses such simple observations to explain pressure, air movement, thunderstorms, lightning and cyclones. NCERT Solutions Class 8 Science Chapter 6 help students solve textbook questions using force per unit area, liquid pressure, atmospheric pressure, wind formation and cyclone safety for 2026-27 learning.
Key Takeaways
- Pressure: Pressure is force per unit area, and its SI unit is pascal.
- Liquid pressure: Liquid pressure increases with the height of the liquid column.
- Wind: Air moves from high-pressure regions to low-pressure regions.
- Cyclone: A cyclone is a rotating system of clouds, winds and rain around low pressure.
NCERT Solutions Class 8 Science Chapter 6 Structure 2026-27
| Exercise Section |
Main Focus |
What Students Practise |
| MCQs |
Liquid pressure, suckers, water tanks and vessels |
Concept application |
| True or False |
Wind, liquid pressure, cyclone eye and safety |
Quick reasoning |
| Descriptive Questions |
Pressure, lightning, storms, cyclones and activities |
Explanation-based answers |
Keep the Curiosity Alive
The textbook exercise in Class 8 Science Chapter 6 Pressure, Winds, Storms, and Cyclones tests pressure, liquid pressure, air pressure, wind, lightning and cyclone formation.
1. Choose the Correct Statement
(i) Look at Fig. 6.21 carefully. Vessel R is filled with water. When pouring of water is stopped, the level of water will be:
(a) the highest in vessel P
(b) the highest in vessel Q
(c) the highest in vessel R
(d) equal in all three vessels
Answer: The correct answer is (d) equal in all three vessels.
The vessels are connected, so water levels become equal after pouring stops. Liquid pressure depends on the height of the liquid column, not vessel shape.
(ii) A rubber sucker M is pressed on a flat smooth surface and N is pressed on a rough surface.
(a) Both M and N will stick to their surfaces.
(b) Both M and N will not stick to their surfaces.
(c) M will stick but N will not stick.
(d) M will not stick but N will stick.
Answer: The correct answer is (c) M will stick but N will not stick.
A rubber sucker sticks better on a smooth surface because air is pushed out properly. On a rough surface, air enters through small gaps.
So, enough pressure difference is not created.
(iii) A water tank is placed on the roof at height H. To get more pressure on the ground floor, one has to:
(a) increase the height H
(b) decrease the height H
(c) replace the tank with another tank of the same height that can hold more water
(d) replace the tank with another tank of the same height that can hold less water
Answer: The correct answer is (a) increase the height H.
Water pressure increases with the height of the water column. A higher tank gives a stronger stream of water from taps below.
(iv) Two vessels A and B contain water up to the same level. PA and PB are pressures at the bottom. FA and FB are forces exerted at the bottom.
(a) PA = PB, FA = FB
(b) PA = PB, FA < FB
(c) PA < PB, FA = FB
(d) PA > PB, FA > FB
Answer: The correct answer is (b) PA = PB, FA < FB.
Pressure at the bottom depends on the height of water. Both vessels have the same water level, so pressure is equal.
Force depends on pressure and area. Vessel B has a larger base area, so force at its bottom is greater.
2. State Whether the Following Statements Are True or False
(i) Air flows from a region of higher pressure to a region of lower pressure.
Answer: True
Air moves from high-pressure areas to low-pressure areas. This movement of air forms wind.
(ii) Liquids exert pressure only at the bottom of a container.
Answer: False
Liquids exert pressure at the bottom and on the sides. In fact, liquids exert pressure in all directions.
(iii) Weather is stormy at the eye of a cyclone.
Answer: False
The eye of a cyclone has the lowest pressure, but the wind is calm there. The surrounding region has strong winds and heavy rainfall.
(iv) During a thunderstorm, it is safer to be in a car.
Answer: True
A car is safer during lightning than standing in the open. The metal body helps conduct electric charge around the passengers.
3. Fig. 6.23 shows a boy lying horizontally and standing vertically on loose sand. In which case does the boy sink more?
Answer: The boy sinks more when he stands vertically.
When he stands, his weight acts on a smaller area of sand.
Pressure = Force / Area
The force is the same in both cases because the boy’s weight is unchanged. In the standing position, the area of contact is smaller.
So, pressure on the sand is higher. This makes him sink more.
When he lies down, his weight spreads over a larger area. So, pressure becomes lower.
4. An elephant stands on four feet. Area covered by one foot is 0.25 m². Weight is 20000 N. Calculate pressure.
Answer: The pressure exerted by the elephant is 20000 N/m², or 20000 Pa.
Given:
Weight of elephant = 20000 N
Area of one foot = 0.25 m²
Total area of four feet = 4 × 0.25 m²
Total area = 1 m²
Formula:
Pressure = Force / Area
Substitution:
Pressure = 20000 N / 1 m²
Pressure = 20000 N/m²
So, pressure = 20000 Pa.
5. Boat A has base area 7 m² with 5 persons. Boat B has base area 3.5 m² with 3 persons. Each person weighs 700 N. Which boat experiences more pressure and by how much?
Answer: Boat B experiences more pressure by 100 N/m².
For Boat A:
Total weight = 5 × 700 N
Total weight = 3500 N
Base area = 7 m²
Pressure = Force / Area
Pressure on Boat A = 3500 / 7
Pressure on Boat A = 500 N/m²
For Boat B:
Total weight = 3 × 700 N
Total weight = 2100 N
Base area = 3.5 m²
Pressure on Boat B = 2100 / 3.5
Pressure on Boat B = 600 N/m²
Difference:
600 - 500 = 100 N/m²
So, Boat B experiences 100 N/m² more pressure.
6. Would lightning occur if air and clouds were good conductors of electricity?
Answer: No, lightning would not occur in the same sudden way.
Normally, air acts as an insulator. Charges build up in clouds until the insulating property of air breaks down.
Then charges flow suddenly and produce lightning. If air and clouds were good conductors, charges would flow gradually.
They would not build up enough to create a sudden bright flash. So, lightning as we see it would not occur.
7. What will happen to the two identical balloons A and B when water is filled into the bottle up to a certain height?
Answer: Both balloons will bulge if they are at the same depth.
They will bulge equally if the holes are at the same height from the water surface.
Liquid pressure depends on the height of the water column above the point. It does not depend on the shape or size of the container.
If balloons A and B are placed at equal depths, pressure on both is equal. So, both balloons bulge to the same extent.
If one balloon is lower, it will bulge more.
8. Explain how a storm becomes a cyclone.
Answer: A storm can become a cyclone over warm ocean water.
Warm ocean water heats the moist air above it. This warm and moist air rises and creates a low-pressure area.
Air from surrounding high-pressure regions rushes in. As the moist air rises, water vapour condenses into raindrops.
Condensation releases heat into the atmosphere. This warms the rising air further and makes it rise even more.
Earth’s rotation makes the moving air spin. A very low-pressure area forms at the centre.
High-speed winds, clouds and rain start rotating around it. This spinning system becomes a cyclone.
9. Fig. 6.25 shows trees along the sea coast in a summer afternoon. Identify which side is land, A or B.
Answer: Side B is land.
During a summer afternoon, land heats faster than sea. Warm air over land rises and creates low pressure.
Cooler air from the sea moves towards land. This is called sea breeze.
The trees bend in the direction of wind movement. So, if wind is blowing from A to B, A is the sea side and B is the land side.
10. Describe an activity to show that air flows from a region of high pressure to a region of low pressure.
Answer: Take two similar balloons and a drinking straw.
Attach one end of the straw to an uninflated balloon. Inflate the second balloon and hold its mouth closed.
Insert the other end of the straw into the inflated balloon. Then allow air to move through the straw.
The inflated balloon becomes smaller. The uninflated balloon becomes larger.
This happens because air pressure is higher inside the inflated balloon. Air moves from the high-pressure balloon to the low-pressure balloon.
Air flow stops when pressure becomes almost equal in both balloons.
11. What is a thunderstorm? Explain the process of its formation.
Answer: A thunderstorm is a storm accompanied by lightning and thunder.
It forms when warm, moist air rises quickly. The rising air expands and cools.
Water vapour condenses and forms clouds. Water droplets join together and become heavier.
They may fall as rain, hail or snow.
Inside the cloud, strong upward and downward winds move water droplets and ice particles. Rubbing between these particles creates electric charges.
When charges build up and flow suddenly, lightning occurs. The rapid heating and expansion of air produces thunder.
12. Explain the process that causes lightning.
Answer: Lightning is caused by a sudden flow of electric charges.
In a thunderstorm, strong winds move up and down inside clouds. Water droplets and ice particles rub against each other.
This rubbing creates static electric charges. Lighter positive ice particles move to the upper part of the cloud.
Heavier negative water droplets move to the lower part. The ground below may become positively charged.
Air normally prevents charges from meeting. When charge build-up becomes very large, air loses its insulating property.
A sudden flow of charges produces a bright flash called lightning.
13. Explain why holes are made in banners and hoardings.
Answer: Holes are made in banners and hoardings to let air pass through.
Strong winds exert pressure on large surfaces. If air cannot pass through, pressure on the banner becomes very high.
The banner or hoarding may tear, bend or fall.
Holes reduce the pressure difference across the surface. This makes the structure safer during strong winds.
Pressure Class 8 Science: Main Ideas From the Chapter
Pressure class 8 science questions become easier when students connect force with area. The same force can produce different pressure depending on the surface area.
Meaning of Pressure
Pressure is force per unit area.
Formula:
Pressure = Force / Area
SI Unit of Pressure
The SI unit of pressure is newton per metre square.
It is also called pascal.
1 Pa = 1 N/m²
Broad Straps and Narrow Straps
Broad straps reduce pressure on shoulders.
They spread the bag’s weight over a larger area.
Sharp Knife and Blunt Knife
A sharp knife has a smaller contact area.
So, it produces more pressure and cuts more easily.
Pointed Nail
The pointed end of a nail has a small area.
It produces high pressure and enters wood easily.
Atmospheric Pressure Class 8: Air Pressure and Winds
Atmospheric pressure class 8 answers should explain that air has weight and exerts pressure. This pressure changes from place to place and causes wind.
Meaning of Atmospheric Pressure
Atmospheric pressure is the pressure exerted by air around us.
Air exerts pressure on all objects.
Rubber Sucker Activity
A rubber sucker sticks when air inside it is pushed out.
Outside air pressure becomes higher than pressure inside the sucker.
This pressure difference keeps it stuck to the surface.
Why We Are Not Crushed
Atmospheric pressure is very large.
We are not crushed because pressure inside our body balances outside pressure.
Formation of Wind
Wind forms because air moves from high pressure to low pressure.
A larger pressure difference creates stronger wind.
Sea Breeze and Land Breeze
During the day, land heats faster than water.
Warm air over land rises and creates low pressure.
Cool sea air moves towards land and forms sea breeze.
At night, the reverse movement forms land breeze.
Lightning Class 8 Science: Formation and Safety
Lightning class 8 science questions often ask formation and safety steps. Lightning can occur within clouds, between clouds or between clouds and the ground.
Thunder
Thunder is the loud sound produced after lightning.
Lightning heats air rapidly and causes sudden expansion.
Lightning Safety
During lightning, stay away from tall objects.
Do not stand near trees, poles or open metal objects.
Do not use an umbrella with a metallic rod.
If in water, come out immediately.
A car or bus is comparatively safer.
Safe Position
Find a low-lying open area.
Crouch down and keep contact with the ground minimum.
Do not lie flat on the ground.
Lightning Conductor
A lightning conductor is a metallic rod fixed on a building.
Its top end is pointed and placed above the building.
Its lower end is buried deep in the ground.
It gives electric charges a safe path into the ground.
Cyclone Class 8 Science: Formation, Damage and Safety
Cyclone class 8 science answers should mention warm ocean water, low pressure, Earth’s rotation and high-speed winds. Cyclones are stronger than regular thunderstorms.
Formation of Cyclone
Cyclones form over warm ocean water.
Warm moist air rises and creates low pressure.
Surrounding air rushes in and starts rotating due to Earth’s rotation.
Eye of Cyclone
The eye is the centre of the cyclone.
It has the lowest pressure, but the wind is calm there.
Damage Caused by Cyclones
Cyclones bring high-speed winds and heavy rainfall.
They can cause storm surges, floods, landslides and power outages.
Sea water may enter farms and reduce soil fertility.
Cyclone Monitoring
The India Meteorological Department monitors cyclones and thunderstorms.
Weather satellites help track cyclone path and intensity.
Cyclone Safety
People in cyclone-prone areas should follow official alerts.
They should keep an emergency kit ready.
During danger, they should move to a designated cyclone shelter.
Useful Links for Class 8 Science