Quick Review Flashcards - Click to flip and test your knowledge!
Question
Pressure is defined as the _____ per unit area.
Answer
force
Question
State the mathematical formula used to compute pressure.
Answer
$\text{Pressure} = \frac{\text{Force}}{\text{Area}}$
Question
What is the standard SI unit of pressure?
Answer
pascal (Pa)
Question
How is one pascal (Pa) expressed in terms of newtons and metres?
Answer
$1\ \text{N/m}^2$
Question
For a constant force, how does increasing the area of contact affect the resulting pressure?
Answer
The pressure decreases.
Question
Why does a school bag with broad straps feel more comfortable than one with narrow straps?
Answer
Broad straps spread the weight over a larger area, reducing the pressure on the shoulders.
Question
Why is it easier to drive a nail into wood using its pointed end rather than its head?
Answer
The smaller area of the pointed end results in a higher pressure for the same force.
Question
What is the purpose of a porter placing a round piece of cloth on their head before carrying a heavy load?
Answer
It increases the area of contact, thereby reducing the pressure exerted by the load.
Question
How does the pressure exerted by a liquid change as the height of the water column increases?
Answer
The pressure increases.
Question
In which direction(s) do liquids exert pressure on the walls of their container?
Answer
In all directions.
Question
Why are overhead water tanks always placed at a significant height?
Answer
To increase the pressure in the taps, resulting in a more powerful stream of water.
Question
Why is the base of a dam built to be much broader than its top?
Answer
To withstand the high horizontal water pressure that exists near the bottom.
Question
The envelope of air that surrounds the Earth is known as the _____.
Answer
atmosphere
Question
Define 'atmospheric pressure'.
Answer
The pressure exerted by the air in the atmosphere around us.
Question
Why is a rubber sucker difficult to pull off a smooth flat surface once pressed against it?
Answer
The external atmospheric pressure is much higher than the reduced air pressure inside the sucker.
Question
Why are humans not crushed by the immense weight of the atmospheric air column?
Answer
The pressure inside the human body balances the external atmospheric pressure.
Question
Air moves from a region of _____ pressure to a region of _____ pressure.
Answer
high; low
Question
How does the magnitude of the pressure difference between two regions affect wind speed?
Answer
A higher pressure difference results in a higher wind speed.
Question
What is the practical unit of air pressure that is equal to $100\ \text{Pa}$?
Answer
millibar (mb)
Question
One hectopascal ($hPa$) is equivalent to how many pascals ($Pa$)?
Answer
$100\ \text{Pa}$
Question
According to the experiment with suspended balloons, high-speed winds are accompanied by _____ air pressure.
Answer
reduced
Question
What causes warm air to rise during the formation of a storm?
Answer
Warm air is lighter than cooler air.
Question
What process occurs when rising warm, moist air expands and cools at great heights?
Answer
Water vapour condenses to form water droplets or ice particles.
Question
How are static electric charges generated within a storm cloud?
Answer
Strong upward and downward winds cause rubbing between water droplets and ice particles.
Question
In a storm cloud, where do the positively charged lighter ice particles typically accumulate?
Answer
In the upper part of the cloud.
Question
In a storm cloud, where do the negatively charged heavier water droplets typically accumulate?
Answer
In the lower part of the cloud.
Question
What happens to the ground and nearby objects when the negatively charged lower part of a cloud moves close to them?
Answer
They become positively charged.
Question
Define 'lightning'.
Answer
A sudden flow of electrical charges producing a bright flash of light when the insulating property of air breaks down.
Question
What physical event causes the loud sound known as thunder?
Answer
Lightning rapidly heats the air, causing it to expand suddenly.
Question
A storm that is accompanied by both lightning and thunder is specifically called a _____.
Answer
thunderstorm
Question
What name is given to local thunderstorms in West Bengal, Bihar, and Jharkhand?
Answer
Kalboishakhi
Question
Why are pre-monsoon thunderstorms in Kerala and Karnataka known as 'mango showers'?
Answer
They support the ripening of mangoes.
Question
Where do cyclones typically form?
Answer
Over warm ocean waters.
Question
What role does the condensation of water vapour play in the intensification of a cyclone?
Answer
It releases heat back into the atmosphere, causing the air to rise further and lowering the pressure.
Question
What force causes the moving air in a cyclone to spin?
Answer
The Earth's rotation.
Question
What is the 'eye' of a cyclone?
Answer
The calm, lowest-pressure region at the centre of the storm.
Question
Describe the weather conditions typically found within the eye of a cyclone.
Answer
The wind is calm and there is no rainfall.
Question
Why does a cyclone gradually lose its strength after reaching land?
Answer
The source of moist air from the ocean is cut off.
Question
What causes the 'wall of water' (storm surge) that floods coastal areas during a cyclone?
Answer
Strong winds pushing ocean water towards the shore.
Question
How can seawater flooding affect farmland fertility during a cyclone?
Answer
The salt in the seawater can make the soil less fertile.
Question
Which organisation in India is responsible for issuing weather reports and cyclone warnings?
Answer
India Meteorological Department (IMD)
Question
During lightning, why should one avoid using an umbrella with a metallic rod?
Answer
Metal is a conductor and can attract lightning, increasing the risk of a strike.
Question
If caught in an open field during lightning, what is the safest physical position to adopt?
Answer
Crouch down low with minimal contact with the ground, rather than lying flat.
Question
Why are passengers inside a bus or car comparatively safer during a thunderstorm?
Answer
The metallic frame of the vehicle acts as a protective shield (Faraday cage).
Question
How high can the storm surge or 'wall of water' be during a severe cyclone?
Answer
Between 3 and 12 metres.
Question
In a cyclone, high-speed winds revolve around a region of _____ pressure.
Answer
very low
Question
What is the peak wind speed recorded for the Amphan cyclone in 2020?
Answer
$270\ \text{km/h}$
Question
What should people living in cyclone-prone areas keep ready to reduce the impact of the disaster?
Answer
An emergency kit with essential items.
Question
How do weather monitoring satellites help in cyclone management?
Answer
They allow for tracking and predicting the path of the cyclone in advance.
Question
Process: Storm formation starts when warm air rises, creating a _____ area.
Answer
low-pressure
Question
Identify the local name for thunderstorms in Assam that help kharif crops grow.
Answer
Bordoisila
Question
What causes the rattling of windows or fluttering of clothes during a windy day?
Answer
The force exerted by the wind, known as wind pressure.
Question
What happens to the size of a balloon if it is connected to a more highly inflated balloon via a straw?
Answer
It increases in size until the air pressure in both balloons is equal.
Question
Why does air escape from an inflated balloon when its mouth is opened?
Answer
Air moves from the high-pressure region inside the balloon to the lower-pressure region outside.
Question
What determines the extent of the bulge in a balloon attached to the bottom of a water pipe?
Answer
The height of the water column in the pipe.
Question
In Activity 6.1, why did balloons on pipes of different diameters bulge to the same extent when water levels were equal?
Answer
Liquid pressure depends on the height of the column, not the total weight or diameter of the pipe.