WBCS Preliminary Question – 2021
73. The ratio of the diameters of moon and earth is nearly —
(A) 1 : 2 (B) 1 : 5 (C) 1 : 4 (D) 1 : 8
Correct Answer: (C) 1 : 4
Explanation: The diameter of the Moon is approximately 3,474 km while Earth’s diameter is about 12,742 km This makes the Moon’s diameter roughly 27% (approx. 1/4) of Earth’s.
- Important Data: The Moon’s mass is about 1/81 of Earth’s, and its gravity is 1/6 of Earth’s gravity.
WBCS Preliminary Question – 2020
59. Identify the correct pairs for Northern Hemisphere:
1. Winter Solstice–Dec 22nd,
2. Autumn Equinox–Sept 23rd,
3. Summer Solstice–June 21st,
4. Spring Equinox–March 21st.
(A) 1 and 2
(B) 2 and 3
(C) 3 and 4
(D) All are correctly matched
Correct Answer: (D) All are correctly matched
Explanation: These dates mark the transition of seasons. During Solstices, the sun reaches its highest or lowest excursion relative to the celestial equator. During Equinoxes, day and night are approximately equal everywhere on Earth.
80. Light from the sun reaches us in nearly —
(A) 2 minutes
(B) 8 minutes
(C) 4 minutes
(D) 16 minutes
Correct Answer: (B) 8 minutes
Explanation: Light travels at 3× 10^8 m/sThe average distance from the Sun to Earth is about 150 million km. It takes approximately 8 minutes and 20 seconds for sunlight to reach Earth.
- Important Data: Light from the Moon reaches Earth in just 1.3seconds.
104. The scale used for measuring the intensity of the earthquake is —
(A) Metric scale
(B) Quake scale
(C) Richter scale
(D) Epicenter scale
Correct Answer: (C) Richter scale
Explanation: The Richter scale measures the magnitude (energy released), while the Mercalli scale measures the intensity (damage caused). Richter is a logarithmic scale, meaning each whole number increase represents a ten-fold increase in measured amplitude.
WBCS Preliminary Question – 2019
49. Mansarovar lake lies in —
(A) Karakoram Range
(B) Pirpanjal Range
(C) Kailas Range
(D) Mahabharata Range
Correct Answer: (C) Kailas Range
Explanation: Lake Mansarovar is located in the Tibet Autonomous Region, near Mount Kailash. It is a high-altitude freshwater lake and is the source of major rivers like the Indus, Brahmaputra (Tsangpo), and Sutlej.
WBCS Preliminary Question – 2018
51. On average, air contains ______ % of water vapour.
(a) 1
(b) 3
(c) 5
(d) 7
Correct Answer: (a) 1
Explanation: Water vapour content in the atmosphere varies from 0% in dry polar regions to 4% in humid tropical regions. On a global average, it is approximately 1% to 2%.
- Important Data: Water vapour is the most potent greenhouse gas in the atmosphere.
WBCS Preliminary Question – 2017
136. India’s share of total land area in the world is about —
(A) 2.4 per cent
(B) 2.8 per cent
(C) 3.2 per cent
(D) 3.6 per cent
Correct Answer: (A) 2.4 per cent
Explanation: India occupies 2.4% of the world’s land area 3.28 million sq. km but supports about 17.5% of the world’s population. This makes India the 7th largest country by area.
WBCS Preliminary Question – 2016
131. Tropopause is: —
(A) A region between troposphere and stratosphere.
(B) A natural umbrella above volcanic eruptions.
(C) Both (A) and (B)
(D) Neither (A) nor (B)
Correct Answer: (A) A region between troposphere and stratosphere.
Explanation: The Tropopause is the atmospheric boundary where the temperature stops decreasing with height. Its height is about 18 km at the equator and 8 km at the poles. It acts as a “lid” for most weather phenomena.
121. For his model of industrial location, Weber makes use of: —
(A) Isogons (B) Isophenes (C) Isodapanes (D) Isotachs
Correct Answer: (C) Isodapanes
Explanation: Alfred Weber’s Theory of Industrial Location uses Isodapanes (lines of equal total transport cost). Isotims are lines of equal transport cost for a single commodity. This model identifies the “Least Cost Location” for industries.
WBCS Preliminary Question – 2015
77. If there were no atmosphere, the earth would have been —
(A) Slightly hot (B) Slightly cold (C) Very hot (D) Very cold
Correct Answer: (D) Very cold
Explanation: Without an atmosphere, there would be no Greenhouse Effect to trap heat. Earth’s average temperature would drop to approximately 18 degree C from the current 15 degree C, making it a frozen, lifeless planet.
86. Geographical concentration of industries generates —
(A) Horizontal linkage only (B) Vertical linkage only (C) Both vertical and horizontal (D) No linkage
Correct Answer: (C) Both vertical and horizontal linkages
Explanation: Industrial clusters (Agglomeration) lead to Vertical linkages (supply chains between raw materials and finished goods) and Horizontal linkages (shared infrastructure, labor pools, and specialized services).
119. In which layer of the atmosphere does ozone act as a UV radiation shield? —
(A) Troposphere (B) Thermosphere (C) Stratosphere (D) Mesosphere
Correct Answer: (C) Stratosphere
Explanation: The “Ozonosphere” is located within the Stratosphere (approx. 15-35km.) It absorbs 97-99 % of the Sun’s medium-frequency ultraviolet light UV-B which otherwise causes skin cancer and DNA damage.
139. One of the characteristics of the atmosphere of prebiotic primitive earth was: —
(A) Absence of hydrogen (B) Absence of water vapour (C) Absence of nitrogen (D) Absence of oxygen
Correct Answer: (D) Absence of oxygen
Explanation: The primitive atmosphere was a “Reducing Atmosphere” consisting of Methane, Ammonia, Water Vapour, and Hydrogen. Free oxygen appeared much later through the process of photosynthesis by cyanobacteria.
178. Theory of Plate Tectonics explains —
(A) Formation of Mountains (B) Sea floor spreading (C) Origin of earthquakes (D) All of the above
Correct Answer: (D) All of the above
Explanation: Proposed in the 1960s, this theory describes the movement of lithospheric plates. It explains Orogeny (mountain building at convergent boundaries), Seismicity, and Sea Floor Spreading at mid-oceanic ridges.
182. An area will be described as urban if it has —
(A) High population (B) Has towns and cities (C) High proportion of non-agriculture pursuits (D) All the above
Correct Answer: (C) High proportion of people in non-agriculture pursuits
Explanation: According to the Census of India, a “Statutory Town” or “Census Town” must have a minimum population of 5,000, and at least 75% of the male main working population must be engaged in non-agricultural pursuits.
WBCS Preliminary Question – 2014
53. El Nino refers to —
(A) Atmospheric (B) Environmental (C) Oceanic (D) Climatic phenomenon
Correct Answer: (C) An Oceanic phenomenon
Explanation: El Niño is the abnormal warming of surface waters in the eastern tropical Pacific Ocean. While it has major atmospheric impacts (Southern Oscillation), it is primarily defined as a periodic fluctuation in sea surface temperature.
WBCS Preliminary Question – 2013
27. Seismograph is: —
(A) Instrument for clouds (B) Recording earthquake tremors (C) Measuring water depth (D) Recording air pressure
Correct Answer: (B) An instrument for recording earthquake tremors
Explanation: A seismograph records the P, S, and Surface waves of an earthquake. The record produced is called a Seismogram.
- Important Data: Fathometer is used for water depth; Barometer for atmospheric pressure.
45. Lines drawn joining places of equal dip angles (inclination) are known as —
(A) Isogonic (B) Isoclinic (C) Agonic (D) Isothermal
Correct Answer: (B) Isoclinic lines
Explanation: Isoclinic lines connect points with equal magnetic dip. Isogonic lines connect points with equal magnetic declination. Agonic lines connect points with zero declination.
61. In terms of area India’s rank in the world is —
(A) 5th (B) 7th (C) 10th (D) 12th
Correct Answer: (B) 7th
Explanation: The sequence by area is: Russia > Canada > USA > China > Brazil > Australia > India. India’s total area is 3,287,263 sq. km
88. Part of earth where life exist is known as —
(A) Lithosphere (B) Hydrosphere (C) Atmosphere (D) Biosphere
Correct Answer: (D) Biosphere
Explanation: The Biosphere is the narrow zone of contact between the Lithosphere (land), Hydrosphere (water), and Atmosphere (air) where all living organisms exist.
75. Endemic plants are those which grow in —
(A) Fresh water (B) Shady places (C) On other plants (D) Geographically limited areas
Correct Answer: (D) Geographically limited areas
Explanation: Endemism is the state of a species being unique to a defined geographic location, such as an island or a specific country. For example, the Western Ghats have many endemic plant species not found anywhere else.
WBCS Preliminary Question – 2012
178. El Nino in the Pacific —
(A) Increases monsoon (B) Decreases monsoon (C) Increases cyclones (D) Decreases cyclones
Correct Answer: (B) Decreases monsoon rainfall over India
Explanation: El Niño shifts the warm water and rising air (low pressure) to the Central/Eastern Pacific, weakening the trade winds. This results in suppressed rainfall or drought conditions during the Indian Summer Monsoon.
WBCS Preliminary Question – 2011
197. The latitude of a place is expressed by its angular distance in relation to —
(A) South Pole (B) North Pole (C) Equator (D) Axis of the Earth
Correct Answer: (C) Equator
Explanation: Latitude is the angular distance of a point on the Earth’s surface, measured in degrees from the center of the Earth, north or south of the Equator 0^121. For his model of industrial location, Weber makes use of: —
(A) Isogons (B) Isophenes (C) Isodapanes (D) Isotachs
Correct Answer: (C) Isodapanes
Explanation: Alfred Weber’s Theory of Industrial Location uses Isodapanes (lines of equal total transport cost). Isotims are lines of equal transport cost for a single commodity. This model identifies the “Least Cost Location” for industries.
WBCS Preliminary Question – 2015
77. If there were no atmosphere, the earth would have been —
(A) Slightly hot (B) Slightly cold (C) Very hot (D) Very cold
Correct Answer: (D) Very cold
Explanation: Without an atmosphere, there would be no Greenhouse Effect to trap heat. Earth’s average temperature would drop to approximately $-18^\circ\text{C}$ (from the current $+15^\circ\text{C}$), making it a frozen, lifeless planet.
86. Geographical concentration of industries generates —
(A) Horizontal linkage only (B) Vertical linkage only (C) Both vertical and horizontal (D) No linkage
Correct Answer: (C) Both vertical and horizontal linkages
Explanation: Industrial clusters (Agglomeration) lead to Vertical linkages (supply chains between raw materials and finished goods) and Horizontal linkages (shared infrastructure, labor pools, and specialized services).
119. In which layer of the atmosphere does ozone act as a UV radiation shield? —
(A) Troposphere (B) Thermosphere (C) Stratosphere (D) Mesosphere
Correct Answer: (C) Stratosphere
Explanation: The “Ozonosphere” is located within the Stratosphere (approx. $15\text{–}35 \text{ km}$). It absorbs $97\text{–}99\%$ of the Sun’s medium-frequency ultraviolet light ($UV\text{-}B$), which otherwise causes skin cancer and DNA damage.
139. One of the characteristics of the atmosphere of prebiotic primitive earth was: —
(A) Absence of hydrogen (B) Absence of water vapour (C) Absence of nitrogen (D) Absence of oxygen
Correct Answer: (D) Absence of oxygen
Explanation: The primitive atmosphere was a “Reducing Atmosphere” consisting of Methane, Ammonia, Water Vapour, and Hydrogen. Free oxygen appeared much later through the process of photosynthesis by cyanobacteria.
178. Theory of Plate Tectonics explains —
(A) Formation of Mountains (B) Sea floor spreading (C) Origin of earthquakes (D) All of the above
Correct Answer: (D) All of the above
Explanation: Proposed in the 1960s, this theory describes the movement of lithospheric plates. It explains Orogeny (mountain building at convergent boundaries), Seismicity, and Sea Floor Spreading at mid-oceanic ridges.
182. An area will be described as urban if it has —
(A) High population (B) Has towns and cities (C) High proportion of non-agriculture pursuits (D) All the above
Correct Answer: (C) High proportion of people in non-agriculture pursuits
Explanation: According to the Census of India, a “Statutory Town” or “Census Town” must have a minimum population of $5,000$, and at least $75\%$ of the male main working population must be engaged in non-agricultural pursuits.
WBCS Preliminary Question – 2014
53. El Nino refers to —
(A) Atmospheric (B) Environmental (C) Oceanic (D) Climatic phenomenon
Correct Answer: (C) An Oceanic phenomenon
Explanation: El Niño is the abnormal warming of surface waters in the eastern tropical Pacific Ocean. While it has major atmospheric impacts (Southern Oscillation), it is primarily defined as a periodic fluctuation in sea surface temperature.
WBCS Preliminary Question – 2013
27. Seismograph is: —
(A) Instrument for clouds (B) Recording earthquake tremors (C) Measuring water depth (D) Recording air pressure
Correct Answer: (B) An instrument for recording earthquake tremors
Explanation: A seismograph records the P, S, and Surface waves of an earthquake. The record produced is called a Seismogram.
- Important Data: Fathometer is used for water depth; Barometer for atmospheric pressure.
45. Lines drawn joining places of equal dip angles (inclination) are known as —
(A) Isogonic (B) Isoclinic (C) Agonic (D) Isothermal
Correct Answer: (B) Isoclinic lines
Explanation: Isoclinic lines connect points with equal magnetic dip. Isogonic lines connect points with equal magnetic declination. Agonic lines connect points with zero declination.
61. In terms of area India’s rank in the world is —
(A) 5th (B) 7th (C) 10th (D) 12th
Correct Answer: (B) 7th
Explanation: The sequence by area is: Russia > Canada > USA > China > Brazil > Australia > India. India’s total area is $3,287,263 \text{ sq. km}$.
88. Part of earth where life exist is known as —
(A) Lithosphere (B) Hydrosphere (C) Atmosphere (D) Biosphere
Correct Answer: (D) Biosphere
Explanation: The Biosphere is the narrow zone of contact between the Lithosphere (land), Hydrosphere (water), and Atmosphere (air) where all living organisms exist.
75. Endemic plants are those which grow in —
(A) Fresh water (B) Shady places (C) On other plants (D) Geographically limited areas
Correct Answer: (D) Geographically limited areas
Explanation: Endemism is the state of a species being unique to a defined geographic location, such as an island or a specific country. For example, the Western Ghats have many endemic plant species not found anywhere else.
WBCS Preliminary Question – 2012
178. El Nino in the Pacific —
(A) Increases monsoon (B) Decreases monsoon (C) Increases cyclones (D) Decreases cyclones
Correct Answer: (B) Decreases monsoon rainfall over India
Explanation: El Niño shifts the warm water and rising air (low pressure) to the Central/Eastern Pacific, weakening the trade winds. This results in suppressed rainfall or drought conditions during the Indian Summer Monsoon.
WBCS Preliminary Question – 2011
197. The latitude of a place is expressed by its angular distance in relation to —
(A) South Pole (B) North Pole (C) Equator (D) Axis of the Earth
Correct Answer: (C) Equator
Explanation: Latitude is the angular distance of a point on the Earth’s surface, measured in degrees from the center of the Earth, north or south of the Equator ($0^\circ$).
WBCS Preliminary Question – 2010
84. Tsunamis are generated by —
(A) Under-sea plate movements (B) Undersea volcanism (C) Tidal change (D) None of the above
Correct Answer: (A) Under-sea plate movements
Explanation: Most tsunamis are caused by vertical displacement of the seafloor during underwater earthquakes at subduction zones. This moves the entire water column, creating massive waves that travel long distances.
WBCS Preliminary Question – 2008
168. The tsunami of Dec 2004 originated from —
(A) Subduction of Indian plate under Myanmar plate (B) Subduction of Myanmar under Indian (C) Trench formation (D) Hawaii
Correct Answer: (A) Subduction of Indian plate under the Myanmar plate
Explanation: This $9.1$ magnitude earthquake occurred off the coast of Sumatra. The Indian Plate subducted beneath the Burma Microplate (part of the Eurasian Plate), causing a massive uplift of the seafloor.
180. Lignite is a type of —
(A) Iron ore (B) Copper (C) Coal (D) Limestone
Correct Answer: (C) Coal
Explanation: Lignite is “Brown Coal,” containing about 40-55% carbon. It is considered the lowest rank of coal. In India, the largest lignite deposits are found in Neyveli, Tamil Nadu.
WBCS Preliminary Question – 2007
184. When a body is raised upwards from the surface of the earth, its weight shall —
(A) Increase (B) Remain same (C) Decrease (D) Fluctuate
Correct Answer: (C) Decrease
Explanation: Weight (W = mg) depends on the acceleration due to gravity (g). The value of $g$ decreases as we move away from the Earth’s center (altitude) and also as we go deeper into the Earth.
WBCS Preliminary Question – 2005
106. The Deccan Lava region was formed during —
(a) Cretaceous (b) Jurassic (c) Triassic (d) Cambrian
Correct Answer: (a) Cretaceous period
Explanation: The Deccan Traps were formed by massive volcanic eruptions (fissure eruptions) at the end of the Cretaceous period (about 6 million years ago. This basaltic lava created the “Regur” or Black Soil of India.
161. Titan is —
(a) Saturn’s largest moon (b) Passenger liner (c) Ancient city (d) Metallic element
Correct Answer: (a) Saturn’s largest moon
Explanation: Titan is the second-largest moon in the solar system (after Ganymede). It is the only moon known to have a dense atmosphere and stable bodies of liquid (methane/ethane) on its surface.
WBCS Preliminary Question – 2004
115. The height of the peak of the world is —
(A) 8,848m (B) 8,567m (C) 8,150m (D) 7,990m
Correct Answer: (A) 8,848m
Explanation: Mount Everest is the highest peak. Recent measurements by Nepal and China have updated the height slightly to 8,848.86m. It is located in the Mahalangur Himal sub-range of the Himalayas.
WBCS Preliminary Question – 2003
141. In areal extent, India’s place among the countries of the world is —
(A) 2nd (B) 4th (C) 5th (D) 7th
Correct Answer: (D) Seventh
Explanation: (Same as Question 61 from 2013). India follows Australia and precedes Argentina in size.
173. Weight of a man is more —
(A) On equator (B) At poles (C) At centre (D) In space
Correct Answer: (B) At poles
Explanation: Earth is an oblate spheroid (bulged at the equator). The distance from the center is least at the poles, making gravity (g )strongest there. Therefore, weight is maximum at the poles and minimum at the equator.
193. The lowermost layer of the atmosphere is —
(A) Troposphere (B) Stratosphere (C) Ionosphere (D) None
Correct Answer: (A) Troposphere
Explanation: The Troposphere contains roughly 80% of the atmosphere’s mass and almost all its water vapour. All weather phenomena (clouds, rain, storms) occur in this layer.
WBCS Preliminary Question – 2002
180. Which one of the following is an estuarine delta? —
(A) Rhine (B) Mississippi (C) Ganga (D) Volga
Correct Answer: (A) Rhine delta
Explanation: An estuarine delta forms when the mouth of a river is submerged. The Rhine and the Seine are examples. Mississippi is a “Bird-foot” delta, and Ganga is an “Arcuate” delta.
140. What is the most widely cultivated fruit in world? —
(A) Banana (B) Apple (C) Guava (D) Grapes
Correct Answer: (A) Banana
Explanation: By volume of production and global consumption, Bananas are the most widely cultivated fruit. India is the largest producer of bananas in the world.
WBCS Preliminary Question – 2001
44. Around the solstices twilight lasts from sunset to sunrise in —
(A) Equatorial (B) Tropical (C) High latitudes (D) Mid latitudes
Correct Answer: (C) High latitudes
Explanation: In high latitudes (Arctic/Antarctic circles), the sun remains just below the horizon during summer solstice nights, leading to continuous twilight (Midnight Sun phenomenon).
87. There is no local time at —
(A) London (B) North and South Poles (C) IDL (D) Magnetic Poles
Correct Answer: (B) North and South Poles
Explanation: At the poles, all lines of longitude converge. Since time zones are based on longitude, “time” becomes arbitrary. Research stations at the poles usually use the time of their home country or supply hub.
168. Term for sandy deserts with characteristic sand dune landscape? —
(A) Reg (B) Erg (C) Hamada (D) Bad land
Correct Answer: (B) Erg
Explanation: An Erg is a “sand sea.” A Reg is a rocky/stony desert surface (desert pavement), and a Hamada is a high, rocky plateau desert.
170. The Earth’s magnetic field —
(A) Never changes (B) Has reversed itself (C) Exact centre (D) Permanent magnet
Correct Answer: (B) Has reversed itself many times
Explanation: This is called “Geomagnetic Reversal.” Evidence from mid-oceanic ridges shows that the North and South magnetic poles swap places every few hundred thousand years. It is generated by the Dynamo effect in the outer core.
WBCS Preliminary Question – 2000
97. Period of revolution is exactly 12 years for —
(A) Mars (B) Jupiter (C) Saturn (D) Uranus
Correct Answer: (B) Jupiter
Explanation: Jupiter takes $11.86$ Earth years to complete one orbit around the sun.
- Data: Saturn takes 29.5 years; Uranus 84 years; Mars 687 days.
99. Lines joining places with the same total transport cost are called —
(A) Isotims (B) Isodapane (C) Isochrones (D) Isopheths
Correct Answer: (B) Isodapane
Explanation: (Repeat concept from 2016). Isochrones join places with equal travel time from a specific point.
39. Most fossils are found in —
(A) Granite (B) Sedimentary (C) Black soil (D) Lava
Correct Answer: (B) Sedimentary rocks
Explanation: Fossils are preserved in layers of sediment (sand, mud) that harden over time. Igneous rocks (Granite, Lava) are too hot during formation, and Metamorphic rocks undergo too much pressure to preserve fossils.
116. Laterite soils are formed due to —
(A) Removal of silicates, lime and organic matter (B) Decaying organic matter (C) Disintegration of lava (D) Exfoliation
Correct Answer: (A) Removal of silicates, lime and organic matter
Explanation: Laterite soil is formed by Leaching in areas of high temperature and high rainfall. Silica is washed away, leaving behind iron and aluminum oxides, making the soil acidic and reddish.
