5th Class General Science Chapter 8 MCQs | Structure of the Earth (زمین کی ساخت) | PakMCQs

Rocks, minerals, and water is correct because the Earth's crust consists of various layers of solid materials and underground water sources below the topsoil.

Underground water, rivers, and lakes is correct because these are the main freshwater sources pumped or diverted for domestic use.

Due to the water cycle (rain and melting snow) is correct because the water lost through evaporation is returned to these bodies via precipitation like rain and melting glaciers.

Earth is correct because it is the only known planet that has the unique combination of atmosphere, water, and temperature required to support living things.

Air, water, soil, light, and temperature is correct as these natural elements are essential for the survival and health of all living organisms.

Due to suitable environmental conditions is correct because the presence of life-supporting resources allows plants, animals, and humans to grow and reproduce.

The inner side of the Earth is correct because exploring the layers beneath the surface helps us understand the planet's structure and composition.

A hard boiled egg is correct because it has distinct internal layers like a shell, white part, and yolk, which help in modeling the Earth's structure.

Into two equal parts is correct because cutting it down the middle reveals the cross-section of all the internal layers for comparison.

Different layers is correct because an egg is composed of separate sections that correspond to the different internal zones of the Earth.

The outer shell is correct as it is the very thin, hard protective covering of the egg, similar to the Earth's crust.

The white part is correct because it occupies the most space between the thin shell and the central yolk.

The yellow yolk is correct because it sits at the very center of the egg, representing the Earth's core in this model.

Three is correct because an egg is used to model the three main divisions of the Earth: the crust, mantle, and core.

Rind is correct as it refers to the thin outer shell of the egg that protects the internal layers.

Geologists is correct because these scientists study the Earth's physical structure and often use simple models like an egg for explanation.

Crust is correct because it is the thin, outermost solid layer of the Earth, just like the egg's shell.

White part is correct because it lies between the shell and the yolk, similar to the mantle which is the middle layer of the Earth.

Core is correct because it is the central and deepest part of the Earth, just as the yolk is the innermost part of the egg.

Crust is correct because it is the outermost solid layer of our planet that covers the mantle.

Crust is correct as it is the solid surface layer that provides the land, soil, and environment necessary for life to exist.

All of the above is correct because mountains, oceans, rivers, deserts, and human cities are all located on the outer crust.

Solid matter is correct because the crust is composed of hard, solid rocks and soil that form the tectonic plates.

5 km to 70 km is correct as the thickness varies, being thinnest under the oceans and thickest under mountain ranges.

About 5 km is correct because oceanic crust is much thinner and denser than the continental crust found under landmasses.

12,800 km is correct because it represents the average straight-line distance from one side of the Earth to the other through its center.

150 million kilometers is correct as it is the average astronomical distance that sunlight travels to reach our planet.

Mantle is correct because it is the thick, middle layer of the Earth situated between the outer crust and the central core.

Mantle is correct because this middle layer occupies nearly 84% of the Earth's total volume.

About 3,900 km is correct because the mantle extends to a vast depth beneath the thin outer crust of the Earth.

Extremely hot and thick fluid like honey is correct because the high temperature and pressure turn rocks into a semi-solid, viscous state.

Lava is correct because when molten rock (magma) from the mantle erupts onto the surface, it is officially called lava.

Volcano eruption is correct because volcanic vents provide a path for the high-pressure molten mantle material to escape to the surface.

Core is correct because it is the innermost layer of the Earth, situated directly beneath the mantle.

Core is correct because heat from the formation of the planet and radioactive decay makes this central part incredibly hot.

5,000°C is correct as the central core reaches temperatures similar to the surface of the Sun due to massive pressure and energy.

Two parts is correct because geologists divide the core into the inner (internal) core and the outer (external) core.

Internal and External core is correct because these two distinct zones have different physical properties and temperatures.

Due to extreme pressure is correct because even though the temperature is very high, the immense weight of the Earth squeezes the atoms into a solid state.

Almost solid is correct because the extreme weight of the Earth's layers compresses this innermost zone into a rigid sphere.

Thick black molten fluid is correct because the slightly lower pressure in the outer zone allows metals to remain in a liquid, flowing state.

Iron and nickel is correct because these heavy metals sank to the center during the Earth's formation, creating its magnetic properties.

Rock weathering is correct because it is the natural process where wind, water, and temperature break down solid rocks into fine soil particles.

A very slow process is correct because breaking down solid, hard rocks into organic fertile soil requires many generations of natural weathering.

About 1000 years is correct because creating even a tiny amount of topsoil requires a very long period of physical and chemical weathering of rocks.

Only a 5cm thick layer is correct as it highlights how precious and valuable our topsoil resources are, given the extremely slow rate of formation.

16% is correct because despite its massive importance, the inner core physically occupies only a small fraction of the total space inside the Earth.

33% is correct because the internal core is highly dense, meaning it contains a massive amount of weight packed into a relatively small volume.

It is made of very heavy material is correct because it consists of tightly packed heavy metals like solid iron and nickel under immense pressure.

Water is correct because it is the most essential natural resource required for the survival of all living things on our planet.

We cannot think of life without it is correct because water is a fundamental requirement for the biological processes of all living organisms.

70% is correct because the majority of our planet is occupied by oceans, seas, and other water bodies.

About 2% is correct because a small but significant portion of global water is locked up as solid ice in the polar regions and high mountains.

About 97% is correct because the vast majority of global water is highly saline ocean water and is not suitable for drinking.

It is salted water is correct because high salt content is harmful to the human body and causes dehydration if consumed.

About one percent is correct because almost all of the Earth's freshwater is either frozen in glaciers or trapped underground, leaving only a tiny fraction accessible.

Acute shortage of water is correct because growing populations and pollution are depleting the limited freshwater resources available on Earth.

We should not waste water is correct because conserving our limited freshwater supply is crucial for the survival of future generations.

Three states is correct because water is unique for existing naturally as a solid (ice), liquid (water), and gas (vapour).

Solid, liquid, and gas is correct as it covers all the physical forms of water like glaciers, ocean water, and atmospheric vapour.

All of the above is correct because glaciers, rain, lakes, springs, and underground aquifers are all primary reservoirs of drinkable water.

Passes through Earth layers and becomes underground water is correct as the soil acts as a channel that pulls the water deep into the ground.

It is filtered by various layers of the Earth is correct because sand and rocks act as a natural filter, trapping dirt as the water seeps through.

Digging wells or using pumps is correct because we must bore holes into the ground to reach the water table and pump the water up for our use.

Rains and melting glaciers is correct because precipitation and warming temperatures in the mountains supply the freshwater that fills river channels.

Summer season is correct because the high temperatures of summer provide the necessary heat to melt mountain ice on a large scale.

Oceans is correct because river systems act as channels that drain the land's excess freshwater back into the massive seas.

Water cycle is correct because it describes the endless movement of water between the Earth's surface and the atmosphere.

The warmth of the Sun is correct because solar energy heats the surface water, converting it into gas (vapour) that rises to form clouds.

As rain or snow is correct because condensation of water vapour in the clouds leads to precipitation depending on the temperature.

All of the above is correct because rainwater naturally travels through smaller streams and rivers to eventually return to the sea.

It becomes part of underground water is correct because the soil and rocks filter and store the absorbed rainwater deep beneath the Earth's surface.

The process repeats again and again is correct because the water cycle is an endless loop of evaporation, condensation, and precipitation.

Due to the continuous water cycle is correct because water is constantly recycled through different states, ensuring the total volume remains constant over time.

Rocks is correct because the solid crust and mantle of our planet are primarily composed of various types of hard stone and mineral structures.

All of the above is correct because sunshine, rain, and wind act as natural forces that wear down hard rocks over long periods.

Weathering is correct because it is the scientific term for the physical and chemical breakdown of rocks by environmental factors.

Soil is correct because soil is created when tiny rock particles mix with organic matter, water, and air over time.

All of the above is correct because soil is a mixture of tiny rock pieces, natural minerals, water, and trapped air spaces.

The upper part is correct because the topsoil covers the solid bedrock of the crust, providing the surface we walk and grow crops on.

It supports plant growth is correct because plants need soil for nutrients and stability, and plants are the foundation of food for all living things.

Components of the soil is correct because these are the vital parts that must be present together to make healthy, functional soil.

Humus is correct because it is the dark, nutrient-rich organic component of soil formed by decomposed organic matter.

By the decay of plants and animals is correct because decomposers break down dead organic waste into this rich, dark soil material.

Retains moisture and makes soil fertile is correct because humus acts like a sponge that holds water and supplies vital nutrients to crops.

Humus is correct because organic matter like decayed leaves settles at the top, making the topsoil rich and fertile.

Grey is correct because the high concentration of organic humus gives the topsoil a dark grey or blackish appearance.

Subsoil is correct because it is the middle layer of soil that lies directly beneath the organic-rich topsoil.

Clay is correct because fine mineral particles like clay leach down from the topsoil and accumulate in the subsoil.

Brown or reddish is correct because the presence of iron minerals and clay in this layer gives it a warm, rusty coloration.

Gravel is correct because the deepest layer sits directly above the bedrock and contains larger pieces of weathered rock and pebbles.

All of the above is correct because environmental factors determine the soil's weight, wetness, color, texture, and size of grains.

Three types is correct because based on the size of the mineral particles, soil is classified into clay, sand, and silt.

Both (A) and (B) is correct because clay, sand, and silt are all primary soil textures used to define different soils.

Types of soil is correct as these three categories represent the main particle sizes found in any soil mixture.

Very small in size is correct because clay has the finest particles of all soil types, measuring less than 0.002 mm.

Soft, sticky, and brownish is correct as the tiny particles of clay trap water, giving the soil a sticky feel and warm color.

It can hold more water is correct because the tiny spaces between clay particles trap and retain moisture for a long time.

It is very hard when dry is correct because dry clay particles bind tightly together, forming a solid, concrete-like structure.

Due to its sticky and hard nature is correct because the soil resists being turned over by agricultural tools when wet or dry.

It can be moulded into any shape is correct because the wet particles slide over each other, allowing you to shape them easily into pottery.

Bricks and pottery is correct because clay holds its shape after drying and becomes extremely strong and durable when baked.

Bigger particles of grey colour and light in weight is correct because sand is made of larger rock grains compared to clay and silt.

Water is drained rapidly is correct because the large gaps between sand particles allow water to filter straight through without being trapped.

Silica grains is correct because quartz or silica is the most common mineral found in sand due to its chemical stability.

Gritty and coarse is correct because the large size of the sand grains creates a rough and abrasive texture.

Because it cannot hold water and nutrients is correct because the rapid drainage washes away the essential moisture needed by plant roots.

Coastal areas or river beds is correct because water action continuously deposits larger rock grains on shores and riverbanks.

A mixture of sand, clay, and humus is correct because silt combines the properties of different soils to create a balanced structure.

Gardening, growth of plants, and crops is correct because the balanced nutrients and moisture in silt are ideal for farming.

Smooth and silky is correct because the medium-sized particles of silt feel very soft when touched.

It can hold more water than sandy soil is correct because its smaller particles trap moisture much better than large sand grains.

It provides water and minerals to plants is correct because the stored moisture dissolves and delivers essential nutrients to the roots.

It holds strongly the plant roots is correct because the cohesive yet soft structure of silt allows roots to anchor firmly and grow.

Water and air is correct because these elements trapped in the soil spaces are crucial for the respiration and hydration of soil organisms.

All of the above is correct because soil provides shelter, protection, and resources for many small animals and burrowing creatures.

Useful nutrients is correct because these decomposers break down complex organic waste into basic elements that plants can easily absorb.

They increase the fertility of the soil is correct because by recycling organic matter, these microbes enrich the soil with natural fertilizers.

Pottery is correct because clay's sticky and moldable nature makes it ideal for shaping into traditional plates, cups, and vases.

Sand is correct because it contains silica, which is the main ingredient melted at high temperatures to create glass products.

Cultivation (farming) is correct because silt's balanced texture and nutrient-rich composition provide the perfect environment for crops to grow.