1. The atmosphere is the envelope of:
A) Rocks
B) Air
C) Water
D) Soil
Answer: B) Air
Explanation: Atmosphere is a mixture of gases surrounding the Earth.
2. Which gas is most abundant in the Earth’s atmosphere?
A) Oxygen
B) Carbon dioxide
C) Nitrogen
D) Argon
Answer: C) Nitrogen
Explanation: Nitrogen makes up ~78% of the atmosphere.
3. The percentage of oxygen in the atmosphere is about:
A) 10%
B) 21%
C) 25%
D) 30%
Answer: B) 21%
Explanation: Oxygen is essential for respiration and combustion.
4. Carbon dioxide forms about what percent of the atmosphere?
A) 0.03–0.04%
B) 1%
C) 2%
D) 5%
Answer: A) 0.03–0.04%
Explanation: Though small in amount, CO₂ is crucial for greenhouse effect.
5. The atmosphere extends up to approximately:
A) 10 km
B) 100 km
C) 500 km
D) 1600 km
Answer: D) 1600 km
Explanation: The atmosphere thins with altitude but extends ~1600 km above Earth.
6. The lowest layer of the atmosphere is:
A) Stratosphere
B) Mesosphere
C) Troposphere
D) Thermosphere
Answer: C) Troposphere
Explanation: It extends ~0–12 km, contains most weather phenomena.
7. Most weather phenomena occur in:
A) Stratosphere
B) Troposphere
C) Mesosphere
D) Exosphere
Answer: B) Troposphere
Explanation: Clouds, winds, rainfall, storms are found here.
8. The upper boundary of the troposphere is called:
A) Mesopause
B) Tropopause
C) Stratopause
D) Thermopause
Answer: B) Tropopause
Explanation: It separates troposphere from stratosphere.
9. The layer of atmosphere where ozone is concentrated is:
A) Troposphere
B) Stratosphere
C) Mesosphere
D) Thermosphere
Answer: B) Stratosphere
Explanation: Ozone absorbs harmful UV radiation from the sun.
10. The protective layer of ozone lies roughly between:
A) 0–10 km
B) 10–50 km
C) 50–80 km
D) 80–100 km
Answer: B) 10–50 km
Explanation: The ozone layer is in the stratosphere.
11. The coldest layer of the atmosphere is:
A) Troposphere
B) Stratosphere
C) Mesosphere
D) Thermosphere
Answer: C) Mesosphere
Explanation: Temperatures fall to –90°C here.
12. The ionosphere is a part of:
A) Troposphere
B) Stratosphere
C) Thermosphere
D) Mesosphere
Answer: C) Thermosphere
Explanation: Contains charged particles; helps in radio communication.
13. The outermost layer of the atmosphere is:
A) Stratosphere
B) Exosphere
C) Mesosphere
D) Thermosphere
Answer: B) Exosphere
Explanation: Extends beyond 700 km; merges into space.
14. The aurora (Northern & Southern lights) occur in:
A) Troposphere
B) Stratosphere
C) Thermosphere (Ionosphere)
D) Mesosphere
Answer: C) Thermosphere (Ionosphere)
Explanation: Caused by solar wind interacting with charged particles.
15. Which layer is called the “weather-making layer”?
A) Stratosphere
B) Mesosphere
C) Troposphere
D) Thermosphere
Answer: C) Troposphere
Explanation: It has water vapor, dust, and weather systems.
16. Jet planes usually fly in:
A) Troposphere
B) Stratosphere
C) Mesosphere
D) Thermosphere
Answer: B) Stratosphere
Explanation: To avoid weather turbulence and clouds.
17. The stratosphere is ideal for flying because:
A) No oxygen
B) No clouds, calm winds
C) High gravity
D) Less radiation
Answer: B) No clouds, calm winds
Explanation: Weather is stable in stratosphere.
18. The percentage of water vapor in atmosphere varies up to:
A) 1%
B) 2%
C) 4%
D) 10%
Answer: C) 4%
Explanation: Varies with climate and altitude.
19. Which gases are called “greenhouse gases”?
A) Nitrogen, Oxygen
B) Carbon dioxide, Methane, Water vapor
C) Hydrogen, Helium
D) Argon, Neon
Answer: B) Carbon dioxide, Methane, Water vapor
Explanation: They trap heat and maintain Earth’s temperature.
20. The lapse rate refers to:
A) Increase of temperature with height
B) Decrease of temperature with height
C) Constant temperature with height
D) Variation of pressure only
Answer: B) Decrease of temperature with height
Explanation: In troposphere, temperature drops ~6.5°C per km.
21. Ozone depletion is mainly caused by:
A) Nitrogen oxides
B) Carbon dioxide
C) Chlorofluorocarbons (CFCs)
D) Methane
Answer: C) Chlorofluorocarbons (CFCs)
Explanation: CFCs break down ozone molecules.
22. The ozone hole is observed mostly over:
A) Arctic region
B) Antarctic region
C) Equator
D) Himalayas
Answer: B) Antarctic region
Explanation: Cold stratospheric clouds over Antarctica accelerate ozone depletion.
23. The atmosphere is held to the Earth by:
A) Gravity
B) Solar radiation
C) Magnetic field
D) Rotation of Earth
Answer: A) Gravity
Explanation: Gravity prevents gases from escaping into space.
24. Air pressure decreases with:
A) Increase in altitude
B) Decrease in altitude
C) No change in altitude
D) Equator only
Answer: A) Increase in altitude
Explanation: Pressure is maximum at sea level and decreases upward.
25. Which layer of the atmosphere protects Earth from meteors?
A) Stratosphere
B) Mesosphere
C) Thermosphere
D) Exosphere
Answer: B) Mesosphere
Explanation: Meteors burn up due to friction in mesosphere.
26. The average temperature at sea level decreases with altitude at the rate of:
A) 3.5°C per km
B) 6.5°C per km
C) 9.8°C per km
D) 2°C per km
Answer: B) 6.5°C per km
Explanation: This is known as the normal lapse rate.
27. The instrument used to measure temperature is:
A) Hygrometer
B) Thermometer
C) Barometer
D) Anemometer
Answer: B) Thermometer
Explanation: Thermometer is used for air and surface temperature.
28. The minimum temperature of the day is usually recorded:
A) At midnight
B) Just before sunrise
C) At noon
D) Evening
Answer: B) Just before sunrise
Explanation: Long cooling during the night makes this the coldest time.
29. The maximum temperature of the day is usually recorded:
A) At noon
B) Around 2–3 pm
C) At sunset
D) At midnight
Answer: B) Around 2–3 pm
Explanation: There is a lag between maximum solar radiation (noon) and heating of surface.
30. The average temperature decreases from:
A) Equator to poles
B) Poles to equator
C) Tropics to equator
D) Oceans to land
Answer: A) Equator to poles
Explanation: Due to decreasing solar intensity and slanting rays.
31. The instrument used to measure solar radiation is:
A) Pyrheliometer
B) Barometer
C) Hygrometer
D) Anemometer
Answer: A) Pyrheliometer
Explanation: It measures direct solar radiation.
32. The heating of atmosphere is mainly due to:
A) Direct sunlight
B) Absorption of terrestrial radiation by gases
C) Earth’s rotation
D) Ocean currents
Answer: B) Absorption of terrestrial radiation by gases
Explanation: Earth’s surface absorbs solar energy and re-emits as longwave radiation.
33. The “Greenhouse Effect” refers to:
A) Absorption of solar radiation directly by gases
B) Trapping of terrestrial radiation by CO₂, CH₄, water vapor
C) Increase in ozone layer
D) Cooling of atmosphere
Answer: B) Trapping of terrestrial radiation by CO₂, CH₄, water vapor
Explanation: Greenhouse gases maintain Earth’s average temperature.
34. The Earth’s average surface temperature is about:
A) 0°C
B) 15°C
C) 30°C
D) 45°C
Answer: B) 15°C
Explanation: Maintained by balance between incoming and outgoing radiation.
35. The difference between maximum and minimum daily temperature is called:
A) Mean temperature
B) Diurnal range
C) Annual range
D) Lapse rate
Answer: B) Diurnal range
Explanation: Indicates variation within a day.
36. The difference between the hottest and coldest month’s mean temperature is called:
A) Annual range of temperature
B) Daily range of temperature
C) Lapse rate
D) Heat budget
Answer: A) Annual range of temperature
Explanation: Shows seasonal variation.
37. Which area has the least annual range of temperature?
A) Continental interiors
B) Coastal regions
C) Deserts
D) Mountain peaks
Answer: B) Coastal regions
Explanation: Oceans moderate temperature variation.
38. Which area has the maximum annual range of temperature?
A) Equatorial region
B) Coastal region
C) Continental interiors (Siberia)
D) Tropical islands
Answer: C) Continental interiors (Siberia)
Explanation: Lack of oceanic influence causes extremes.
39. The heat received by Earth from the sun is called:
A) Insolation
B) Reflection
C) Albedo
D) Radiation
Answer: A) Insolation
Explanation: Insolation = incoming solar radiation.
40. The proportion of solar radiation reflected back is called:
A) Albedo
B) Insolation
C) Refraction
D) Scattering
Answer: A) Albedo
Explanation: Earth’s average albedo = ~30%.
41. The heat balance of Earth means:
A) Equal input and output of radiation
B) Only incoming heat
C) Only outgoing heat
D) Oceanic heat flow
Answer: A) Equal input and output of radiation
Explanation: Ensures average global temperature stability.
42. Areas of low pressure are usually associated with:
A) Cloudy and rainy weather
B) Clear skies
C) Extreme cold
D) None of the above
Answer: A) Cloudy and rainy weather
Explanation: Rising air cools, condenses, and forms clouds.
43. Areas of high pressure are usually associated with:
A) Clear skies and dry weather
B) Storms
C) Rainfall
D) Monsoons
Answer: A) Clear skies and dry weather
Explanation: Descending air suppresses cloud formation.
44. The instrument used to measure air pressure is:
A) Thermometer
B) Barometer
C) Hygrometer
D) Anemometer
Answer: B) Barometer
Explanation: Standard unit = millibars (hPa).
45. Standard atmospheric pressure at sea level is:
A) 760 mm of mercury / 1013 mb
B) 500 mm of mercury
C) 100 mb
D) 1000 mm of mercury
Answer: A) 760 mm of mercury / 1013 mb
Explanation: This is the normal sea-level pressure.
46. Pressure decreases with altitude at the rate of:
A) 1 mb per 10 m
B) 1 mb per 50 m
C) 1 mb per 100 m
D) 1 mb per 500 m
Answer: C) 1 mb per 100 m (approx.)
Explanation: On average, pressure decreases by ~1 mb for every 10 m in the lower atmosphere, but generalized as ~100 mb per km.
47. The equatorial low-pressure belt is also called:
A) Doldrums
B) Horse latitudes
C) Polar front
D) Trade wind belt
Answer: A) Doldrums
Explanation: Near the equator, air rises due to intense heating.
48. The subtropical high-pressure belts are also called:
A) Doldrums
B) Horse latitudes
C) Westerlies
D) Polar highs
Answer: B) Horse latitudes
Explanation: Calm regions around 30° N and S latitude.
49. The subpolar low-pressure belts are located around:
A) 30° latitude
B) 45°–60° latitude
C) Equator
D) Poles
Answer: B) 45°–60° latitude
Explanation: Caused by convergence of cold polar and warm westerly winds.
50. The polar regions are zones of:
A) Low pressure
B) High pressure
C) Variable pressure
D) None of these
Answer: B) High pressure
Explanation: Cold dense air creates high pressure at the poles.
51. Winds blow due to:
A) Earth’s rotation only
B) Pressure differences
C) Solar radiation only
D) Ocean currents
Answer: B) Pressure differences
Explanation: Air moves from high-pressure to low-pressure areas.
52. The force that initiates the movement of air is:
A) Coriolis force
B) Centrifugal force
C) Pressure gradient force
D) Frictional force
Answer: C) Pressure gradient force
Explanation: The difference in pressure causes air to flow.
53. The apparent deflection of winds due to Earth’s rotation is called:
A) Centripetal force
B) Coriolis force
C) Gradient force
D) Geostrophic force
Answer: B) Coriolis force
Explanation: In the Northern Hemisphere winds deflect to the right, in the Southern Hemisphere to the left.
54. Coriolis force is maximum at:
A) Equator
B) Poles
C) Tropics
D) 30° latitude
Answer: B) Poles
Explanation: It is zero at the equator and increases towards the poles.
55. Winds parallel to isobars under the influence of Coriolis force are called:
A) Geostrophic winds
B) Local winds
C) Cyclones
D) Trade winds
Answer: A) Geostrophic winds
Explanation: These balance pressure gradient and Coriolis forces.
56. Winds spiraling into a low-pressure system are called:
A) Cyclones
B) Anticyclones
C) Trade winds
D) Westerlies
Answer: A) Cyclones
Explanation: Cyclones have converging winds with rising air.
57. Winds spiraling out of a high-pressure system are called:
A) Cyclones
B) Anticyclones
C) Westerlies
D) Hurricanes
Answer: B) Anticyclones
Explanation: Anticyclones have diverging winds with descending air.
58. Trade winds blow from:
A) Subtropical highs to equatorial lows
B) Subpolar lows to subtropical highs
C) Poles to equator
D) Equator to subtropics
Answer: A) Subtropical highs to equatorial lows
Explanation: They blow between 30° and the equator, deflected by Coriolis force.
59. In the Northern Hemisphere, trade winds blow from:
A) NE to SW
B) NW to SE
C) SE to NW
D) SW to NE
Answer: A) NE to SW
Explanation: They originate from the northeast due to Coriolis effect.
60. In the Southern Hemisphere, trade winds blow from:
A) SE to NW
B) SW to NE
C) NE to SW
D) NW to SE
Answer: A) SE to NW
Explanation: Deflected to the left in the Southern Hemisphere.
61. The belt of calm air around the equator where trade winds converge is called:
A) Horse latitudes
B) Doldrums
C) Polar front
D) Westerlies
Answer: B) Doldrums
Explanation: Characterized by low pressure and weak winds.
62. Westerlies blow between:
A) 0° and 30° latitude
B) 30° and 60° latitude
C) 60° and 90° latitude
D) Equator and poles
Answer: B) 30° and 60° latitude
Explanation: They blow from subtropical highs to subpolar lows.
63. Polar easterlies blow from:
A) Poles to subpolar lows
B) Equator to poles
C) Tropics to equator
D) Poles to tropics
Answer: A) Poles to subpolar lows
Explanation: Very cold winds deflected by Coriolis force.
64. The convergence of westerlies and polar easterlies occurs at:
A) Equator
B) Tropic of Cancer
C) Polar front (60° latitude)
D) Poles
Answer: C) Polar front (60° latitude)
Explanation: Polar front is the meeting zone of cold polar air and warm westerlies.
65. Jet streams are high-altitude winds that blow in:
A) Troposphere
B) Stratosphere
C) Tropopause
D) Exosphere
Answer: C) Tropopause
Explanation: Strong narrow currents in the upper troposphere/lower stratosphere.
66. The velocity of jet streams is highest in:
A) Winter
B) Summer
C) Monsoon
D) Spring
Answer: A) Winter
Explanation: Temperature gradient between equator and poles is maximum in winter.
67. The subtropical jet stream is strongest at about:
A) 10° latitude
B) 30° latitude
C) 45° latitude
D) 60° latitude
Answer: B) 30° latitude
Explanation: Located near the subtropical high-pressure belt.
68. The polar jet stream is located near:
A) 30° latitude
B) 60° latitude
C) 90° latitude
D) Equator
Answer: B) 60° latitude
Explanation: Near the subpolar low-pressure belt.
69. Monsoon winds are seasonal winds that reverse due to:
A) Earth’s rotation
B) Pressure difference between land and sea
C) Ocean currents
D) Jet streams only
Answer: B) Pressure difference between land and sea
Explanation: Caused by differential heating of land and ocean.
70. The Indian summer monsoon is characterized by winds blowing from:
A) Land to sea
B) Sea to land
C) Poles to equator
D) East to west
Answer: B) Sea to land
Explanation: Moist winds from Indian Ocean bring rainfall.
71. Local hot dry wind of North India during summer is called:
A) Chinook
B) Bora
C) Loo
D) Foehn
Answer: C) Loo
Explanation: Hot winds blowing in May–June, raising temperatures.
72. The warm dry wind of USA and Canada that melts snow is called:
A) Bora
B) Foehn
C) Chinook
D) Loo
Answer: C) Chinook
Explanation: Known as “snow-eater” in the Rockies.
73. The warm dry wind on the leeward side of the Alps is called:
A) Chinook
B) Bora
C) Foehn
D) Harmattan
Answer: C) Foehn
Explanation: Brings sudden rise in temperature in Europe.
74. The dry, dusty wind blowing from the Sahara to West Africa is called:
A) Loo
B) Harmattan
C) Bora
D) Sirocco
Answer: B) Harmattan
Explanation: Reduces humidity, often called “doctor wind”.
75. Cyclones in the Northern Hemisphere rotate:
A) Clockwise
B) Anticlockwise
C) North to South
D) Randomly
Answer: B) Anticlockwise
Explanation: Due to Coriolis force, cyclones rotate anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
76. The actual amount of water vapor present in the air is called:
A) Relative humidity
B) Absolute humidity
C) Specific humidity
D) Dew point
Answer: B) Absolute humidity
Explanation: It is measured in grams of water vapor per cubic meter of air.
77. Relative humidity is the ratio of:
A) Actual water vapor to maximum possible water vapor capacity
B) Maximum water vapor to actual water vapor
C) Precipitation to evaporation
D) Air temperature to dew point
Answer: A) Actual water vapor to maximum possible water vapor capacity
Explanation: Expressed as a percentage.
78. The temperature at which air becomes saturated and condensation begins is called:
A) Melting point
B) Boiling point
C) Dew point
D) Frost point
Answer: C) Dew point
Explanation: Below this temperature, condensation occurs.
79. When dew point is below 0°C, water vapor directly changes into ice crystals. This is called:
A) Condensation
B) Freezing
C) Sublimation (Frost)
D) Evaporation
Answer: C) Sublimation (Frost)
Explanation: Water vapor converts directly into solid form.
80. Clouds are formed due to:
A) Condensation of water vapor
B) Evaporation of oceans
C) Cooling of soil
D) Movement of air only
Answer: A) Condensation of water vapor
Explanation: Tiny water droplets or ice crystals form clouds.
81. Which clouds are highest in the atmosphere?
A) Cirrus
B) Cumulus
C) Stratus
D) Nimbus
Answer: A) Cirrus
Explanation: Found at 6,000–12,000 m; thin, feathery clouds.
82. Which clouds are known as “fair weather clouds”?
A) Cumulus
B) Cirrus
C) Stratus
D) Nimbus
Answer: A) Cumulus
Explanation: Puffy, cotton-like clouds seen on sunny days.
83. Which clouds are rain-bearing?
A) Cirrus
B) Cumulus
C) Stratus
D) Nimbus
Answer: D) Nimbus
Explanation: “Nimbus” means rain cloud (e.g., cumulonimbus).
84. The instrument used to measure humidity is:
A) Hygrometer
B) Thermometer
C) Barometer
D) Rain gauge
Answer: A) Hygrometer
Explanation: It measures water vapor content in the air.
85. The instrument used to measure rainfall is:
A) Barometer
B) Rain gauge
C) Hygrometer
D) Pyrheliometer
Answer: B) Rain gauge
Explanation: Collects and measures precipitation.
86. The process by which water vapor changes into liquid is:
A) Evaporation
B) Condensation
C) Sublimation
D) Transpiration
Answer: B) Condensation
Explanation: It forms dew, fog, or clouds.
87. Precipitation in the form of ice pellets is called:
A) Snow
B) Sleet
C) Hail
D) Frost
Answer: B) Sleet
Explanation: Frozen raindrops or refrozen ice pellets.
88. Precipitation in the form of large ice balls is called:
A) Snow
B) Hail
C) Sleet
D) Graupel
Answer: B) Hail
Explanation: Produced by violent updrafts in cumulonimbus clouds.
89. Orographic rainfall occurs when:
A) Air rises due to mountain barriers
B) Air heats up over deserts
C) Cold air meets warm air
D) Cyclone develops
Answer: A) Air rises due to mountain barriers
Explanation: Common on windward side of mountains.
90. Convectional rainfall is common in:
A) Polar regions
B) Equatorial regions
C) Temperate zones
D) Deserts
Answer: B) Equatorial regions
Explanation: Caused by intense heating and vertical air currents.
91. Cyclonic rainfall occurs due to:
A) Cooling of air at high altitude
B) Convergence of warm and cold air masses
C) Mountains
D) Ocean currents
Answer: B) Convergence of warm and cold air masses
Explanation: Typical of temperate and tropical cyclones.
92. Heavy rainfall on one side of the mountain and dry conditions on the other side is called:
A) Rainfall effect
B) Desertification
C) Rain shadow effect
D) Cyclonic effect
Answer: C) Rain shadow effect
Explanation: The leeward side remains dry.
93. The world’s highest rainfall is recorded at:
A) Cherrapunji (India)
B) Mawsynram (India)
C) Columbia (South America)
D) Hawaii
Answer: B) Mawsynram (India)
Explanation: Meghalaya, India, receives ~11,872 mm annually.
94. Desert regions receive rainfall less than:
A) 50 cm
B) 25 cm
C) 75 cm
D) 100 cm
Answer: B) 25 cm
Explanation: By definition, deserts get less than 25 cm annually.
95. Köppen’s classification of climate is based on:
A) Latitude
B) Vegetation & Temperature
C) Rainfall & Temperature
D) Ocean currents
Answer: C) Rainfall & Temperature
Explanation: Köppen classified climates using both precipitation and temperature.
96. The letter “A” in Köppen’s classification stands for:
A) Arid
B) Equatorial (Tropical)
C) Temperate
D) Polar
Answer: B) Equatorial (Tropical)
Explanation: Hot, humid equatorial climate.
97. The letter “B” in Köppen’s classification stands for:
A) Desert & Steppe (Dry)
B) Tropical
C) Temperate
D) Polar
Answer: A) Desert & Steppe (Dry)
Explanation: Low-rainfall, arid climates.
98. The letter “E” in Köppen’s classification stands for:
A) Equatorial
B) Dry
C) Polar
D) Highland
Answer: C) Polar
Explanation: Very cold climates like tundra and ice cap.
99. The Indian monsoon is an example of:
A) Planetary wind
B) Local wind
C) Seasonal reversal of winds
D) Polar front
Answer: C) Seasonal reversal of winds
Explanation: Summer monsoon blows sea to land; winter monsoon land to sea.
100. The atmosphere is important for life on Earth because it:
A) Provides oxygen and CO₂
B) Regulates temperature through greenhouse effect
C) Protects from UV radiation and meteors
D) All of the above
Answer: D) All of the above
Explanation: Atmosphere sustains life, regulates climate, and shields Earth.