Earth, Weather and Atmosphere MCQs

Solved Everyday Science MCQs on the layers of the atmosphere and Earth, earthquakes, volcanoes, tsunamis, plate tectonics, weather and the monsoon.

1. 1

   In which layer of the atmosphere does almost all weather occur?

   AMesosphereBStratosphereCTroposphereDThermosphere

   Correct answer: C. Troposphere

   The troposphere, the lowest layer, contains most of the air's mass and water vapour, so clouds and rain form there.

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2. 2

   Most meteors burn up in which layer of the atmosphere?

   AStratosphereBExosphereCTroposphereDMesosphere

   Correct answer: D. Mesosphere

   Meteors burn up from friction in the mesosphere, creating "shooting stars".

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3. 3

   The layer of the atmosphere that reflects radio waves, allowing long-distance radio communication, is the:

   AExosphereBTroposphereCOzone layerDIonosphere

   Correct answer: D. Ionosphere

   The ionosphere contains charged particles that bounce certain radio waves back to Earth.

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4. 4

   The innermost layer of the Earth is the:

   AMantleBOuter coreCCrustDInner core

   Correct answer: D. Inner core

   The inner core is a solid ball made mostly of iron and nickel. The outer core around it is liquid.

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5. 5

   The Earth's core is made mainly of:

   ACarbon and hydrogenBSilicon and oxygenCIron and nickelDGold and silver

   Correct answer: C. Iron and nickel

   The movement of liquid iron in the outer core generates the Earth's magnetic field.

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6. 6

   The thinnest layer of the Earth is the:

   ACrustBMantleCInner coreDOuter core

   Correct answer: A. Crust

   The crust is only about 5–70 km thick, very thin compared with the mantle and the core.

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7. 7

   The theory that the Earth's outer shell is divided into large moving plates is called:

   APlate tectonicsBBig Bang theoryCTheory of relativityDContinental shelf theory

   Correct answer: A. Plate tectonics

   Plate movements cause earthquakes, volcanoes and mountain building. The Himalayas formed as the Indian plate pushed into the Eurasian plate.

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8. 8

   The ancient supercontinent that later broke apart into today's continents is called:

   APangaeaBLaurasia onlyCAtlantisDGondwana only

   Correct answer: A. Pangaea

   Pangaea existed about 300–200 million years ago. It split into Laurasia in the north and Gondwana in the south.

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9. 9

   The point on the Earth's surface directly above where an earthquake starts is called the:

   ACraterBEpicentreCFocusDFault

   Correct answer: B. Epicentre

   The earthquake starts at the focus (hypocentre) underground. The epicentre is the point directly above it.

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10. 10

    The Richter scale was developed to measure the:

    AMagnitude of earthquakesBIntensity of rainfallCHeight of wavesDSpeed of wind

    Correct answer: A. Magnitude of earthquakes

    Charles Richter developed it in 1935. Today scientists mostly use the related moment magnitude scale.

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12. 11

    Molten rock beneath the Earth's surface is called:

    AMagmaBBasaltCLavaDSediment

    Correct answer: A. Magma

    Molten rock is called magma underground and lava once it erupts onto the surface.

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13. 12

    A tsunami is most commonly caused by:

    AThe Moon's gravityBStrong windsCHeavy rainfallDUndersea earthquakes

    Correct answer: D. Undersea earthquakes

    Sudden movement of the sea floor in an undersea earthquake displaces huge volumes of water.

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14. 13

    Rising and falling of sea level twice a day, known as tides, are caused mainly by the gravitational pull of the:

    ASun onlyBMoonCMarsDEarth's core

    Correct answer: B. Moon

    The Moon's gravity is the main cause of tides. The Sun also has a smaller effect.

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15. 14

    The monsoon rains in Pakistan mainly occur during:

    AOctober to NovemberBDecember to FebruaryCMarch to AprilDJuly to September

    Correct answer: D. July to September

    The summer monsoon brings most of Pakistan's annual rainfall between July and September.

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16. 15

    Powerful rotating tropical storms that form over warm oceans are called cyclones in the Indian Ocean and _____ in the Atlantic.

    AMonsoonsBBlizzardsCHurricanesDTornadoes

    Correct answer: C. Hurricanes

    The same kind of storm is called a hurricane in the Atlantic, a typhoon in the north-west Pacific and a cyclone in the Indian Ocean.

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17. 16

    The instrument used to measure rainfall is the:

    AAnemometerBRain gaugeCThermometerDBarometer

    Correct answer: B. Rain gauge

    A rain gauge collects and measures rain, usually in millimetres.

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18. 17

    Dew forms when:

    ASnow meltsBRain evaporatesCWater vapour in the air condenses on cool surfacesDClouds rise

    Correct answer: C. Water vapour in the air condenses on cool surfaces

    At night, surfaces cool below the dew point and water vapour condenses on them as droplets.

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19. 18

    The process by which water changes into water vapour is called:

    ACondensationBEvaporationCPrecipitationDSublimation

    Correct answer: B. Evaporation

    Evaporation drives the water cycle. Condensation forms clouds, and precipitation returns water as rain or snow.

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20. 19

    Which gas makes up about 21% of the Earth's atmosphere?

    ACarbon dioxideBArgonCOxygenDNitrogen

    Correct answer: C. Oxygen

    Oxygen is about 21% of the air and nitrogen about 78%.

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21. 20

    A violently rotating column of air extending from a thunderstorm to the ground is called a:

    AMonsoonBTornadoCTsunamiDCyclone

    Correct answer: B. Tornado

    Tornadoes are smaller than cyclones but can have extremely fast winds.

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