Atmosphere - Practice Test 1

Attempt the quiz above first, then review every question with its correct answer and a short explanation below.

1. Q1.Which gas is most abundant in the Earth's atmosphere?

   • A.Oxygen
   • B.Nitrogen✓ Correct Answer
   • C.Argon
   • D.Carbon Dioxide

   Explanation: Nitrogen makes up about 78% of the atmosphere.

2. Q2.What is the percentage of Oxygen in the atmosphere?

   • A.78%
   • B.21%✓ Correct Answer
   • C.0.93%
   • D.0.03%

   Explanation: Oxygen constitutes approximately 21% of the atmosphere.

3. Q3.Which layer of the atmosphere contains the Ozone layer?

   • A.Troposphere
   • B.Stratosphere✓ Correct Answer
   • C.Mesosphere
   • D.Thermosphere

   Explanation: The Ozone layer is found in the Stratosphere (15-35 km), protecting us from UV rays.

4. Q4.All weather phenomena (rain, fog, hail) occur in which layer?

   • A.Troposphere✓ Correct Answer
   • B.Stratosphere
   • C.Mesosphere
   • D.Exosphere

   Explanation: The Troposphere is the lowest layer where all weather activities take place.

5. Q5.The coldest layer of the atmosphere is:

   • A.Troposphere
   • B.Stratosphere
   • C.Mesosphere✓ Correct Answer
   • D.Thermosphere

   Explanation: The Mesosphere is the coldest layer, with temperatures dropping to -90°C.

6. Q6.Radio waves are reflected back to Earth from which layer?

   • A.Troposphere
   • B.Ionosphere (Thermosphere)✓ Correct Answer
   • C.Stratosphere
   • D.Mesosphere

   Explanation: The Ionosphere (part of Thermosphere) contains charged particles that reflect radio waves.

7. Q7.In which layer do meteors burn up upon entering the atmosphere?

   • A.Troposphere
   • B.Stratosphere
   • C.Mesosphere✓ Correct Answer
   • D.Exosphere

   Explanation: Meteors burn up in the Mesosphere due to friction.

8. Q8.Jet aircrafts usually fly in the:

   • A.Lower Troposphere
   • B.Lower Stratosphere✓ Correct Answer
   • C.Mesosphere
   • D.Thermosphere

   Explanation: The lower Stratosphere provides ideal flying conditions (no clouds/weather).

9. Q9.The boundary between Troposphere and Stratosphere is called:

   • A.Tropopause✓ Correct Answer
   • B.Stratopause
   • C.Mesopause
   • D.Thermopause

   Explanation: The Tropopause marks the top of the Troposphere.

10. Q10.Which gas is transparent to incoming solar radiation but opaque to outgoing terrestrial radiation (Greenhouse Effect)?

    • A.Oxygen
    • B.Nitrogen
    • C.Carbon Dioxide✓ Correct Answer
    • D.Argon

    Explanation: CO2 traps heat radiating from Earth, causing the Greenhouse Effect.

11. Q11.Normal Lapse Rate is the decrease of temperature with height at the rate of:

    • A.1°C per 165 meters✓ Correct Answer
    • B.1°C per 100 meters
    • C.10°C per 1 km
    • D.5°C per 1 km

    Explanation: In the Troposphere, temperature drops by 1°C for every 165m ascent (or 6.5°C per km).

12. Q12.The amount of solar energy received by the Earth is called:

    • A.Insolation✓ Correct Answer
    • B.Radiation
    • C.Albedo
    • D.Convection

    Explanation: Insolation stands for Incoming Solar Radiation.

13. Q13.The reflected amount of solar radiation from the Earth's surface without heating it is called:

    • A.Insolation
    • B.Albedo✓ Correct Answer
    • C.Isotherm
    • D.Scattering

    Explanation: Earth's average albedo is about 30-35%.

14. Q14.Which surface has the highest Albedo?

    • A.Fresh Snow✓ Correct Answer
    • B.Forest
    • C.Ocean
    • D.Sand

    Explanation: Fresh snow reflects up to 80-90% of sunlight.

15. Q15.Atmospheric pressure is measured by:

    • A.Thermometer
    • B.Barometer✓ Correct Answer
    • C.Hygrometer
    • D.Anemometer

    Explanation: A Barometer measures atmospheric pressure.

16. Q16.Lines joining places of equal pressure are called:

    • A.Isotherms
    • B.Isobars✓ Correct Answer
    • C.Isohyets
    • D.Isohalines

    Explanation: Isobars connect points of equal atmospheric pressure.

17. Q17.Wind blows from:

    • A.Low pressure to High pressure
    • B.High pressure to Low pressure✓ Correct Answer
    • C.High temperature to Low temperature
    • D.Low humidity to High humidity

    Explanation: Winds always blow from areas of High Pressure to Low Pressure.

18. Q18.The Coriolis Force is caused by:

    • A.Earth's Revolution
    • B.Earth's Rotation✓ Correct Answer
    • C.Gravitation
    • D.Tides

    Explanation: Earth's rotation deflects winds to the right in the Northern Hemisphere (Coriolis effect).

19. Q19.Due to Coriolis force, winds deflect to which direction in the Northern Hemisphere?

    • A.Left
    • B.Right✓ Correct Answer
    • C.Upwards
    • D.Downwards

    Explanation: Winds deflect to the Right in North, Left in South (Ferrel's Law).

20. Q20.The Equatorial Low Pressure Belt is also known as:

    • A.Horse Latitudes
    • B.Doldrums✓ Correct Answer
    • C.Roaring Forties
    • D.Polar High

    Explanation: It is a zone of calm winds known as the Doldrums (ITCZ).