Understanding the composition of the Earth’s atmosphere is crucial for various competitive exams like the OSSSC LSI (OSSSC Livestock Inspector), Forester FG (Forester Forest Guard). Here are 30 multiple-choice questions (MCQs) along with detailed explanations to help you grasp this topic thoroughly.
- The hot and dry winds that help in the ripening of grapes in the Alps region are known as ________.
A. Chinook
B. Foehn
C. Mistral
D. Roaring Forties
Answer: Option B
Explanation: Foehn is a type of dry, warm, down-slope wind that occurs in the lee (downwind side) of a mountain range, aiding in the ripening of grapes in the Alps region. - Approximately what is the quantum of pressure exerted by the atmosphere at sea level?
A. One kg per sq km
B. One kg per sq mtr
C. Five kg per sq cm
D. Five kg per sq mtr
Answer: Option B
Explanation: The pressure exerted by the atmosphere at sea level is approximately one kg per square meter. - What is the percentage of Nitrogen in the Earth’s atmosphere?
A. 0.94
B. 0.03
C. 78.03
D. 85.02
Answer: Option C
Explanation: Nitrogen constitutes approximately 78.03 percent of the Earth’s atmosphere, making it the most abundant gas. - At low elevations, which among the following clouds are found?
A. Cirrus
B. Nimbus
C. Cumulus
D. Stratus
Answer: Option B
Explanation: Nimbostratus clouds typically form at low elevations, often referred to as fog when occurring at ground level. - Why do jet aircrafts fly easily and smoothly in the lower stratosphere?
A. There are no clouds or water vapor.
B. There are no vertical winds.
C. Both 1 and 2
D. Neither 1 nor 2
Answer: Option C
Explanation: Jet aircrafts fly easily in the lower stratosphere due to the absence of clouds or water vapor and the absence of vertical winds. - What is the most important factor in thunderstorm development?
A. Atmospheric stability
B. Atmospheric instability
C. Abundance of moisture
D. Temperature inversion
Answer: Option B
Explanation: Thunderstorm development primarily depends on atmospheric instability. - The intensity of insolation depends on which of the following?
A. Altitude
B. Nature of terrain
C. Wind
D. Latitude
Answer: Option D
Explanation: The intensity of insolation varies with latitude, among other factors. - What is the innermost layer of the Earth known as?
A. Lithosphere
B. Mesosphere
C. Asthenosphere
D. Barysphere
Answer: Option D
Explanation: The innermost layer of the Earth is called the Barysphere or Core. - Which statement is incorrect?
A. Roaring forties are the southern latitudes where Westerlies are prevalent
B. Monsoons are local seasonal winds
C. Doldrum belt lies between 10°N and 10°S latitudes
D. Horse latitudes are found between Trade winds and Westerlies
Answer: Option B
Explanation: Monsoons are not rainstorms but seasonal winds. - Why is the evening sun not as hot as the mid-day sun?
A. In the evening, radiations travel slowly
B. In the evening, the temperature of the sun decreases
C. Ozone in the atmosphere absorbs more light in the evening
D. In the evening, radiations travel a larger distance through the atmosphere
Answer: Option D
Explanation: The evening sun is less hot as the radiations travel a larger distance through the atmosphere. - How does the water content in the atmosphere change with temperature?
A. Is independent of temperature
B. Increases as temperature increases
C. Decreases as temperature increases
D. Either increases or decreases with temperature increase
Answer: Option C
Explanation: As temperature increases, the water content in the atmosphere decreases due to increased air capacity to hold water molecules. - Consider the following statements regarding tropical cyclones:
Tropical cyclones have circular isobars.
Tropical cyclones originate entirely within the tropical air mass.
The intensity and magnitude of hurricanes generally exceed those of typhoons.
Tropical cyclones are more destructive than western disturbances.
Select the correct answer by using the following codes:
A. 1, 2, and 4
B. 1 only
C. 2 and 3
D. 3 and 4
Answer: Option A
Explanation: Tropical cyclones have circular isobars and originate entirely within the tropical air mass. They are characterized by strong winds, heavy rain, and a spiral arrangement of thunderstorms. Additionally, they are more destructive than western disturbances, causing disruptions to international shipping and occasionally resulting in shipwrecks. - Agents of fog formation do not include ________
A. High relative humidity
B. Diurnal temperatures of short ranges
C. Winter season
D. Rapid radiation
Answer: Option B
Explanation: Agents of fog formation exclude diurnal temperatures of short ranges. Diurnal temperature range (DTR) reflects within-day temperature variability and weather stability but is not directly involved in fog formation. - Which force primarily determines wind movement and velocity?
A. Gravitational force
B. Centrifugal force
C. Frictional force
D. Pressure gradient force
Answer: Option D
Explanation: The pressure gradient force is the most influential in determining wind movement and velocity. It arises from differences in air pressure between locations and drives air from high-pressure areas to low-pressure areas, creating wind. - Atmospheric humidity is measured by ________
A. Psychrometer
B. Anemometer
C. Lysimeter
D. Hydrometer
Answer: Option A
Explanation: Atmospheric humidity is measured by a psychrometer, which utilizes wet-bulb and dry-bulb temperature readings. - Which layer of the atmosphere is the warmest?
A. Thermosphere
B. Troposphere
C. Stratosphere
D. Mesosphere
Answer: Option A
Explanation: The thermosphere, located above the mesosphere, is the warmest layer of the atmosphere. - Which statement regarding Trade Winds is not true?
A. They blow from the Horse Latitudes to the Doldrums
B. They are deflected to the right to become South-East Trades in the southern hemisphere
C. They are constant in strength and direction
D. They sometimes contain intense depressions
Answer: Option B
Explanation: Trade winds in the Southern Hemisphere are deflected to the left due to the Coriolis effect, not to the right. - Choose the correct option with the correct sequence of the layers of the atmosphere
A. Mesophere Ionosphere Exosphere Troposphere Stratosphere
B. Ionosphere Exosphere Mesosphere Stratosphere Troposphere
C. Exosphere Troposphere Ionosphere Mesosphere Stratosphere
D. Troposphere Stratosphere Mesosphere Ionosphere Exosphere
Answer: Option D
Explanation: The correct sequence of atmospheric layers is Troposphere, Stratosphere, Mesosphere, Ionosphere, and Exosphere. - Which statement is true of anticyclones in the southern hemisphere?
A. The air moves in a circular manner
B. Pressure increases from the outside to the center
C. They often form over continents
D. The air moves in an anti-clockwise direction
Answer: Option D
Explanation: In the Southern Hemisphere, anticyclones exhibit clockwise air movement due to the Coriolis effect. - Countries favorably influenced by Westerlies are ________
A. Western Europe, British Columbia, and East of U.S.
B. South-West Africa and South Chile
C. New Zealand
D. All of these
Answer: Option D
Explanation: Countries favorably influenced by Westerlies include Western Europe, British Columbia, East of the U.S., South-West Africa, South Chile, and New Zealand. - Which characteristics apply to a depression in the southern hemisphere?
I. It is a mass of air whose isobars form an oval or circular shape
II. Pressure is high in the center and decreases towards the outside
III. Air moves anti-clockwise
A. I only
B. II only
C. I and III
D. All three
Answer: Option A
Explanation: In the southern hemisphere, depressions are characterized by circular isobars and anti-clockwise air movement. - Which of the following are true regarding the ionosphere? I. It is the uppermost layer of the atmosphere, II. The molecules and atoms of nitrogen and oxygen in this layer absorb a part of solar radiation and become ionized, III. This layer is responsible for reflecting back the radio wave transmitted from the earth
A. I and II
B. I and II
C. II and III
D. I II and III
Answer: Option C
Explanation : The following that are true regarding ionosphere are The molecules and atoms of nitrogen and oxygen in this layer absorb a part of solar radiation and become ionized and This layer is responsible for reflecting back the radio wave transmitted from the earth. - Arrange the following gases of the atmosphere in increasing order by volume:,I. Nitrogen,II. Oxygen,III. Carbon dioxide,IV. Argon
A. I II III IV
B. I II IV III
C. III IV II I
D. IV III II I
Answer: Option C
Explanation : Gases of the atmosphere in increasing order by volume are Carbon dioxide, Argon, Oxygen and Nitrogen. - Wind in the Southern hemisphere is deflected towards left due to ________
A. Temperature variations
B. Rotation of the earth
C. Difference in pressure
D. Difference in water content
Answer: Option B
Explanation : Because the Earth rotates on its axis, circulating air is deflected toward the right in the Northern Hemisphere and toward the left in the Southern Hemisphere. This deflection is called the Coriolis effect. - Local thunderstorms ‘Nor westers’ are prominent in ________
A. Punjab
B. West Bengal
C. Andhra Pradesh
D. Tamil Nadu
Answer: Option B
Explanation : Local thunderstorms ‘Nor westers’ are prominent in West Bengal. Kalbaishakhi is a local rain fall and thunder storm. They generally move from West to East. - Which of the following winds is incorrectly paired with the area in which it prevails?
A. Berg wind – South eastern Africa
B. Karaburan – Tarim basin of Sinkiang
C. Southerly Burster – New South Wales
D. Hurricanes – New Zealand
Answer: Option D
Explanation : A hurricane is a type of storm called a tropical cyclone, which forms over tropical or subtropical waters. Only tropical cyclones that form over the Atlantic Ocean or eastern Pacific Ocean are called “hurricanes.” - Consider the following statements regarding the distribution and pattern of isotherms,1. In the northern hemisphere, isotherms bend sharply equator-ward over the continents during winter.,2. Temperature gradients are greater in summer than in winter in the northern hemisphere.,Which of the statement(s) given above is/are correct?
A. 1 only
B. 2 only
C. Both 1 and 2
D. Neither 1 nor 2
Answer: Option A
Explanation : In the northern hemisphere, isotherms bend sharply equator-ward over the continents during winter. Large landmasses in the Northern hemisphere cause isotherms to bend toward the equator in winter and poles in summer as they change their temperature much more than the water. - Consider the following statements:,1. Either of the two belts over the oceans at about 30° to 35° N and S Latitudes is known as Horse Latitude.,2. Horse latitudes are low pressure belts.,Which of the statements given above is/are correct?
A. 1 only
B. 2 only
C. Both 1 and 2
D. Neither 1 nor 2
Answer: Option A
Explanation : Either of the two belts over the oceans at about 30° to 35° N and S latitudes is known as Horse Latitude. Horse latitude, either of two subtropical atmospheric high-pressure belts that encircle Earth around latitudes 30°– 35° N and 30°– 35° S and that generate light winds and clear skies. Because they contain dry subsiding air, they produce arid climates in the areas below them. - Warm dry winds blowing down the east slopes of Rockies are known as ________
A. Mistral
B. Nor’ westers
C. Foehn
D. Chinook
Answer: Option D
Explanation : Warm dry winds blowing down the east slopes of rockies is known as chinook. They are a type of warm, dry wind that occur on the downward slope of a mountain when warm air has lost its moisture. - The study of the processes of atmosphere is called as
A. Astrology
B. Meteorology
C. Seismology
D. Astronomy
Answer: Option B
Explanation : It is the branch of science which is concerned with the processes of atmosphere e.g. forecasting weather. Meteorology is the scientific study of the atmosphere that focuses on weather processes and forecasting.
