NCERT MCQ Solutions for Class 8 Science Curiosity Chapter 6 Pressure, Winds, Storms and Cyclones

Pressure as force per unit area and states its SI unit is newton per square metre (N/m²), also called pascal (Pa). This unit helps measure how force is distributed over a surface. Air pressure and liquid pressure are both expressed in pascal or related units. 

Activities and examples that air flows from regions of higher pressure to regions of lower pressure. This movement is responsible for the formation of wind, including land and sea breezes and storm systems like cyclones.

When air is blown into a balloon, it fills up and expands in all directions. This shows that air exerts pressure on the walls of the balloon from within, demonstrating that pressure in gases acts equally in all directions. 

Atmospheric pressure is the pressure exerted by the air in the atmosphere on all objects. This pressure is significant and balanced by the pressure inside our bodies, preventing us from being crushed by the air above.

Rubber sucker activity to show how air pressure acts on objects. When pressed against a surface, the air inside is expelled, and the greater outside air pressure makes it stick, showing the strong force exerted by surrounding air.

When pressure difference increases rapidly between two areas, air moves faster from the high-pressure region to the low-pressure region, creating high-speed winds. Using activities like balloon inflations and paper strips to show wind patterns. 

The air blown between the balloons creates a low-pressure zone. The higher pressure on the outer sides pushes them inward, bringing them closer. This activity in the chapter shows how fast-moving air reduces pressure and causes surrounding air to exert force.

Storms can develop into cyclones under certain weather conditions. When warm, moist air rises and the Earth’s rotation causes the air to spin, a cyclone may form with strong winds and heavy rainfall around a low-pressure center.

In a cyclone, the region at the center with the lowest pressure is called the eye. It is surprisingly calm and clear, even while the surrounding areas experience violent winds and heavy rain due to the spinning system.

Water pressure increases with depth. Since the bottom of a dam experiences more horizontal pressure due to water, the base must be broader to withstand that pressure and provide structural support. 

Lightning rapidly heats the surrounding air, causing it to expand suddenly. This expansion creates a shock wave which is heard as thunder. This process as part of a thunderstorm, often observed during heavy rainfall and strong winds.

A lightning conductor is a pointed metallic rod fixed to the top of buildings. One end is buried in the ground. It safely channels electric charges from lightning into the Earth, protecting the building from damage, as described in the textbook.

High-speed winds create a low-pressure region above the roof. If the pressure difference between the inside and outside is large, the higher pressure below can lift the roof off. Keeping windows and doors open to balance pressure and prevent this. 

Strong winds cause water droplets and ice particles to rub against each other in clouds. This rubbing leads to electric charges separating in the cloud, which later causes lightning when these opposite charges discharge.

Wind forms when warm air rises creating a low-pressure region. Cooler air from high-pressure regions flows in to fill the space. Cycle through sea and land breeze examples and confirms pressure difference as the main cause of wind movement.

During daytime, land or sand gets heated more quickly than water. As a result, the air above the land becomes warmer, rises and creates a low-pressure zone. This sets up wind movement from the sea towards land, known as sea breeze.

At night, the land loses heat faster than water. So, the air over land becomes cooler and heavier, creating a high-pressure area. The warmer air over the sea rises, forming a low-pressure area. Air moves from land to sea, resulting in a land breeze.

Warm air is lighter and expands. Due to its lower density, it rises upwards and creates a region of low pressure. This rising of warm air is a key factor in the formation of winds, storms and cyclones.

The importance of cyclone warning systems to inform people before a cyclone hits. These systems help issue timely warnings through sirens, radio or mobile alerts. Preparedness can reduce damage to life and property during such natural disasters.

Against going near electric poles or power lines during storms and cyclones, as they may carry live current. Instead, it advises moving to strong buildings, staying updated on weather forecasts and keeping essentials ready for emergencies.

A cyclone emergency kit must include basic survival items such as a flashlight, batteries, clean drinking water and dry food. These items to help people stay safe and functional in case of power cuts and disrupted supplies during a cyclone.

Satellites help scientists observe and track the formation, movement and intensity of cyclones. Images and data from satellites are used in forecasting and issuing timely warnings, thus playing a vital role in disaster management and preparedness.

Wind speed depends on how much pressure difference exists between two regions. A greater difference causes faster wind as air rushes to balance pressure. This principle is demonstrated in various activities involving paper, balloons and weather systems.

Farmers to take protective steps like storing seeds and grains in waterproof containers, securing livestock and protecting shelters. These measures help minimize damage from water and wind during cyclones and ensure quick recovery after the storm.

Staying in strong concrete buildings (pucca houses) during a cyclone. Such structures are less likely to collapse or get blown away by strong winds, offering better protection compared to huts, tents or sheds which are easily damaged.

After a cyclone alert is issued, its advises moving to safe shelter immediately and staying tuned to weather updates. Being informed helps people act quickly and avoid risky situations like flooding, power lines or collapsing buildings during the storm.

Touches upon how our ears feel pressure changes, like during air travel. The ear can sense even small changes in atmospheric pressure, which is why it sometimes feels blocked or pops when pressure around us changes rapidly.

During high-speed winds, keeping windows and doors open allows air pressure to equalize inside and outside the house. If windows are tightly shut, high internal pressure can push the roof upwards, increasing the risk of blow-off.

Strong cyclones bring intense rainfall and fast-moving winds. These result in uprooted trees, damaged houses, flooded fields and broken power lines. The combined effect of rain and wind causes widespread destruction, making cyclone preparedness very important.

During the day, land heats up faster than sea. Warm air over land rises creating a low-pressure zone. Cooler air from the sea moves in to take its place. This movement of air from sea to land forms the sea breeze, as explained in the chapter.