Pressure, Winds, Storms and Cyclones — Class 8 MCQs with Answers

Pressure, Winds, Storms and Cyclones — important questions & MCQs with answers (Class 8 Science)

6 solved questions from this chapter's difficulty levels, each with its answer and explanation. Tap an option to check yourself.

0 of 6 answered

1. Q1 of 6Easy

   Pressure is defined as:

   Aforce per unit areaBforce × areaCforce + areaDarea per unit force
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   Answer: force per unit area

   Explanation: Pressure = Force ÷ Area — it measures how concentrated a force is over a surface, not force times area or force plus area.

2. Q2 of 6Easy

   The pressure exerted by the air around us is called:

   Awater pressureBmuscular pressureCatmospheric pressureDcharge
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   Answer: atmospheric pressure

   Explanation: The pressure the surrounding air exerts on everything is called atmospheric pressure, distinct from pressure from water or muscles.

3. Q3 of 6Medium

   In a thundercloud, electric charges build up because strong winds cause:

   Athe Sun to shineBice particles and water droplets to rub togetherCthe ground to shakeDfires to start
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   Answer: ice particles and water droplets to rub together

   Explanation: Strong up-and-down winds inside a thundercloud make ice particles and water droplets collide and rub together, building up separated electric charges.

4. Q4 of 6Medium

   Under certain conditions, a strong storm may develop into a:

   ArainbowBcalm dayCcycloneDdesert
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   Answer: cyclone

   Explanation: Under the right conditions of warmth and moisture over the sea, a strong storm can intensify further into a full cyclone.

5. Q5 of 6Hard

   The same person stands first on one foot, then on two feet. The pressure on the floor is:

   Agreater on two feetBgreater when standing on one footCthe same either wayDzero on one foot
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   Answer: greater when standing on one foot

   Explanation: Standing on one foot puts the same body weight on half the contact area, so pressure = force ÷ area is greater on one foot than on two.

6. Q6 of 6Hard

   Winds ultimately blow because the Sun heats the Earth:

   Aevenly everywhereBonly at nightCnot at allDunevenly, creating pressure differences
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   Answer: unevenly, creating pressure differences

   Explanation: The Sun heats different parts of Earth's surface unevenly, creating regions of unequal air pressure, and air flowing from high to low pressure is wind.

Pressure, Winds, Storms and Cyclones notes: key concepts (Class 8 Science)

This chapter connects a simple idea — pressure — to the weather. Pressure is the force acting on each unit of area (Pressure = Force ÷ Area), measured in pascals (1 Pa = 1 N/m²), so the same force on a smaller area gives a higher pressure. Air presses on everything as atmospheric pressure, and differences in air pressure make winds blow from high-pressure to low-pressure regions. Warm air rises to create low pressure that cooler air rushes in to fill — the engine behind breezes, thunderstorms with lightning, and powerful cyclones, against which we protect ourselves using lightning conductors and IMD warnings.

Pressure

The force acting on each unit of area, given by Pressure = Force ÷ Area. Its SI unit is the pascal (Pa), equal to one newton per square metre.

Pressure and area

For the same force, a smaller area gives a higher pressure (a sharp knife, a nail tip) and a larger area gives a lower pressure (wide straps, camel feet, tractor tyres).

Pressure by liquids and gases

Liquids and gases exert pressure in all directions on the walls of their container; a liquid also settles at the same level in connected vessels.

Atmospheric pressure

The pressure exerted by the air around us; it holds a rubber sucker onto a smooth surface and decreases as you go higher up.

Wind

Moving air. Wind blows from a region of high pressure to a region of low pressure, and a bigger pressure difference gives a stronger wind.

Warm air rises

Heated air expands, becomes lighter and rises, leaving a low-pressure area that cooler, denser air from higher-pressure surroundings moves in to fill.

Sea and land breezes

By day the land heats faster, so cooler sea air blows in as a sea breeze; by night the land cools faster and a land breeze blows out to sea.

Thunderstorms

Form where there is moisture and strong winds; rising, cooling vapour condenses into clouds, and rubbing ice and water droplets build up electric charges.

Lightning and its conductor

Lightning is the discharge when positive and negative charges meet, within a cloud, between clouds or between a cloud and the ground; a lightning conductor safely carries it to the earth.

Cyclones

Violent storms that form over warm seas as warm air rises and cool air rushes in; they cause flooding, salt-damaged farmland, blocked roads and power cuts.

Cyclone safety

Weather satellites and the India Meteorological Department (IMD) track cyclones and issue warnings; people should keep an emergency kit and move to a cyclone shelter.