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.
Answer: B
Explanation: The Sun is the gravitational center of the Solar System, around which all planets revolve.
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.