CLASS 9 SOCIAL SCIENCE
CHAPTER 1: OCEANS AND LIFE
50 MULTIPLE-CHOICE QUESTIONS (MCQs)
1. What is ocean relief?
(A) The movement of ocean water
(B) The physical features of the ocean floor
(C) The temperature of ocean water
(D) The depth of the atmosphere
Answer: (B) The physical features of the ocean floor
2. Which is the deepest place on Earth mentioned in the chapter?
(A) Gulf of Khambhat
(B) Mid-Atlantic Ridge
(C) Mariana Trench
(D) Continental Shelf
Answer: (C) Mariana Trench
3. Which is the world’s longest mountain range hidden beneath the ocean?
(A) Himalayas
(B) Mid-Ocean Ridge
(C) Andes
(D) Alps
Answer: (B) Mid-Ocean Ridge
4. What is a continental shelf?
(A) The deepest part of an ocean
(B) A flat-topped underwater mountain
(C) The submerged, shallow edge of a continent
(D) A narrow ocean current
Answer: (C) The submerged, shallow edge of a continent
5. Which ocean-floor feature is a steep slope marking the true edge of a continent?
(A) Continental slope
(B) Abyssal plain
(C) Guyot
(D) Seamount
Answer: (A) Continental slope
6. What is an abyssal plain?
(A) A shallow coastal area
(B) A vast, flat, and deep ocean floor
(C) A mountain rising above sea level
(D) A narrow river valley
Answer: (B) A vast, flat, and deep ocean floor
7. What is a seamount?
(A) A shallow continental shelf
(B) An underwater mountain that does not reach the sea surface
(C) A deep ocean trench
(D) A coastal beach formed by waves
Answer: (B) An underwater mountain that does not reach the sea surface
8. What is a guyot?
(A) A flat-topped underwater mountain
(B) A deep ocean current
(C) A coastal sand dune
(D) A type of ocean wave
Answer: (A) A flat-topped underwater mountain
9. What primarily causes ordinary ocean waves?
(A) The gravitational pull of the Moon alone
(B) Winds blowing across the water
(C) The movement of ships
(D) The rotation of fish schools
Answer: (B) Winds blowing across the water
10. What is the wavelength of a wave?
(A) The vertical height of a wave
(B) The time required for a wave to pass
(C) The horizontal distance between two consecutive crests or troughs
(D) The number of waves passing a point each second
Answer: (C) The horizontal distance between two consecutive crests or troughs
11. What is a wave crest?
(A) The lowest part of a wave
(B) The highest point of a wave
(C) The distance between two waves
(D) The time taken by a wave
Answer: (B) The highest point of a wave
12. Which of the following is an erosional landform created by wave action?
(A) Beach
(B) Sea arch
(C) Sand dune formed inland
(D) River delta
Answer: (B) Sea arch
13. Which of the following is a depositional feature formed by waves?
(A) Sea cave
(B) Sea stack
(C) Beach
(D) Sea arch
Answer: (C) Beach
14. What is a tsunami?
(A) A regular daily rise in sea level
(B) A giant wave mainly caused by an underwater earthquake
(C) A warm ocean current
(D) A small wave produced only by ships
Answer: (B) A giant wave mainly caused by an underwater earthquake
15. What are tides?
(A) Continuous streams of ocean water flowing in definite directions
(B) The rhythmic rise and fall of ocean water
(C) Waves caused only by strong winds
(D) Permanent changes in ocean depth
Answer: (B) The rhythmic rise and fall of ocean water
16. What is a high tide?
(A) The lowest level of ocean water near the shore
(B) The highest level of ocean water covering more of the shore
(C) The complete absence of ocean water
(D) A current flowing towards the open sea
Answer: (B) The highest level of ocean water covering more of the shore
17. What is a low tide?
(A) The highest level of ocean water
(B) A giant wave caused by an earthquake
(C) The lowest level of ocean water as it moves away from the shore
(D) A warm ocean current
Answer: (C) The lowest level of ocean water as it moves away from the shore
18. When do spring tides occur?
(A) During the first-quarter and third-quarter Moon phases
(B) During the full Moon and new Moon
(C) Only during solar eclipses
(D) Only during winter
Answer: (B) During the full Moon and new Moon
19. Why are spring tides particularly strong?
(A) The Sun and Moon are aligned, strengthening their combined gravitational effect
(B) Ocean currents stop completely
(C) Winds disappear over the oceans
(D) The Earth stops rotating
Answer: (A) The Sun and Moon are aligned, strengthening their combined gravitational effect
20. When do neap tides occur?
(A) During the full Moon only
(B) During the new Moon only
(C) During the first-quarter and third-quarter Moon phases
(D) Only during cyclones
Answer: (C) During the first-quarter and third-quarter Moon phases
21. What happens during neap tides?
(A) The difference between high tide and low tide becomes smaller
(B) The difference between high tide and low tide becomes unusually large
(C) Ocean water stops moving
(D) All coastal areas become permanently submerged
Answer: (A) The difference between high tide and low tide becomes smaller
22. How do high tides help ships enter harbours?
(A) They reduce the depth of the water
(B) They raise the water level near the shore
(C) They stop all ocean currents
(D) They remove underwater mountains
Answer: (B) They raise the water level near the shore
23. Which Indian region is mentioned as having a tidal range of about 12 metres?
(A) Gulf of Kutch
(B) Gulf of Khambhat
(C) Chilika Lake
(D) Malabar Coast
Answer: (B) Gulf of Khambhat
24. Which of the following is identified as a major tidal energy site in India?
(A) Gulf of Kutch
(B) Thar Desert
(C) Deccan Plateau
(D) Aravalli Hills
Answer: (A) Gulf of Kutch
25. What are ocean currents?
(A) The regular rise and fall of sea level
(B) Continuous streams of ocean water flowing in definite directions
(C) Underwater mountains
(D) Waves formed only near beaches
Answer: (B) Continuous streams of ocean water flowing in definite directions
26. Which force associated with Earth’s rotation affects ocean currents?
(A) Frictional force alone
(B) Coriolis force
(C) Magnetic force alone
(D) Nuclear force
Answer: (B) Coriolis force
27. Which of the following can influence ocean currents?
(A) Winds, Earth’s rotation, temperature, and salinity differences
(B) Only the activities of fishermen
(C) Only the colour of ocean water
(D) Only the movement of ships
Answer: (A) Winds, Earth’s rotation, temperature, and salinity differences
28. What are warm ocean currents?
(A) Currents flowing from colder regions
(B) Currents flowing from warmer regions
(C) Currents that remain completely stationary
(D) Currents found only beneath sea ice
Answer: (B) Currents flowing from warmer regions
29. Which warm ocean current helps keep Norwegian waters relatively warm?
(A) Labrador Current
(B) Gulf Stream
(C) Canary Current
(D) Benguela Current
Answer: (B) Gulf Stream
30. Which cold current supports the formation of sea ice and icebergs along Canada’s eastern coast?
(A) Gulf Stream
(B) Brazil Current
(C) Labrador Current
(D) Kuroshio Current
Answer: (C) Labrador Current
31. What are fishing grounds where warm and cold currents meet often rich in?
(A) Nutrients
(B) Freshwater only
(C) Desert sand
(D) Volcanic ash only
Answer: (A) Nutrients
32. What is the main purpose of an early warning system for cyclones and tsunamis?
(A) To increase ocean temperatures
(B) To detect hazards and issue timely warnings
(C) To stop all ocean waves
(D) To prevent fishing activities permanently
Answer: (B) To detect hazards and issue timely warnings
33. What was one important outcome of the Indian Ocean tsunami of 2004?
(A) Countries strengthened tsunami warning and disaster-management systems
(B) Ocean currents permanently stopped
(C) All maritime zones were abolished
(D) Tidal energy became unavailable
Answer: (A) Countries strengthened tsunami warning and disaster-management systems
34. Which organisation collaborates with the India Meteorological Department in establishing the Storm Surge Early Warning System mentioned in the chapter?
(A) SEBI
(B) INCOIS
(C) TRAI
(D) RBI
Answer: (B) INCOIS
35. What is the main purpose of the Storm Surge Early Warning System (SSEWS)?
(A) To forecast cyclone-induced storm surges and coastal inundation
(B) To measure the population of coastal cities
(C) To increase the depth of harbours
(D) To regulate international trade taxes
Answer: (A) To forecast cyclone-induced storm surges and coastal inundation
36. What does the GEMINI device help fishermen access?
(A) Only entertainment programmes
(B) Safety alerts, weather information, and fishing-related advisories
(C) Only banking services
(D) Only information about road traffic
Answer: (B) Safety alerts, weather information, and fishing-related advisories
37. How does the GEMINI device transfer satellite information to fishermen’s mobile phones?
(A) Through Bluetooth
(B) Through underwater cables only
(C) Through printed newspapers
(D) Through radio broadcasts alone
Answer: (A) Through Bluetooth
38. What are marine resources?
(A) Resources found only on land
(B) Materials and features in oceans that have intrinsic or economic value
(C) Resources available only in deserts
(D) Manufactured goods found in factories
Answer: (B) Materials and features in oceans that have intrinsic or economic value
39. Which of the following is a marine living resource?
(A) Offshore oil
(B) Natural gas
(C) Fish
(D) Metallic minerals
Answer: (C) Fish
40. Which of the following is a marine non-living resource?
(A) Fish
(B) Marine vegetation
(C) Marine organisms
(D) Offshore oil
Answer: (D) Offshore oil
41. What is the Blue Economy?
(A) The use of ocean resources without considering environmental effects
(B) The sustainable use of ocean resources to promote economic growth, livelihoods, and jobs while preserving marine ecosystems
(C) An economy based only on farming
(D) An economic system that prohibits all ocean-related activities
Answer: (B) The sustainable use of ocean resources to promote economic growth, livelihoods, and jobs while preserving marine ecosystems
42. Which Sustainable Development Goal is associated with protecting ocean life?
(A) SDG 2: Zero Hunger
(B) SDG 4: Quality Education
(C) SDG 14: Life Below Water
(D) SDG 16: Peace, Justice and Strong Institutions
Answer: (C) SDG 14: Life Below Water
43. What is a nautical mile equal to?
(A) 1,000 metres
(B) 1,500 metres
(C) 1,852 metres
(D) 2,500 metres
Answer: (C) 1,852 metres
44. What is the territorial sea?
(A) An ocean area closest to a country where it exercises sovereignty subject to certain international rights
(B) An area belonging exclusively to all private shipping companies
(C) An area beyond every country’s maritime jurisdiction
(D) A freshwater lake within a country
Answer: (A) An ocean area closest to a country where it exercises sovereignty subject to certain international rights
45. Up to what distance from the baseline does the contiguous zone extend, according to the chapter?
(A) 12 nautical miles
(B) 24 nautical miles
(C) 100 nautical miles
(D) 200 nautical miles
Answer: (B) 24 nautical miles
46. Up to what distance from the baseline can a country’s Exclusive Economic Zone (EEZ) extend?
(A) 12 nautical miles
(B) 24 nautical miles
(C) 100 nautical miles
(D) 200 nautical miles
Answer: (D) 200 nautical miles
47. What special rights does a country have in its Exclusive Economic Zone?
(A) The right to prohibit every foreign ship from peaceful passage
(B) Special rights to explore, exploit, and use ocean resources
(C) Complete ownership of all international waters
(D) The right to control every ocean on Earth
Answer: (B) Special rights to explore, exploit, and use ocean resources
48. What are the high seas?
(A) Waters located entirely within a country’s territorial sea
(B) Waters that belong exclusively to coastal towns
(C) International waters beyond the EEZs of all countries
(D) Inland waters found within continents
Answer: (C) International waters beyond the EEZs of all countries
49. What is the main purpose of COLREGs?
(A) To regulate fishing prices
(B) To prevent collisions between ships at sea
(C) To determine the depth of ocean trenches
(D) To establish the prices of marine resources
Answer: (B) To prevent collisions between ships at sea
50. What is the main purpose of the MARPOL Convention?
(A) To increase maritime pollution
(B) To establish fishing seasons only
(C) To reduce pollution from ships
(D) To determine the boundaries of the continental shelf
Answer: (C) To reduce pollution from ships
CLASS 9 SOCIAL SCIENCE
CHAPTER 1: OCEANS AND LIFE
ASSERTION–REASON QUESTIONS
Choose the correct option for each question:
(A) Both Assertion (A) and Reason (R) are true, and Reason (R) is the correct explanation of Assertion (A).
(B) Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of Assertion (A).
(C) Assertion (A) is true, but Reason (R) is false.
(D) Assertion (A) is false, but Reason (R) is true.
1. Assertion (A): The continental shelf is rich in marine life and resources such as oil and gas.
Reason (R): The continental shelf is the submerged, shallow edge of a continent.
Answer: (B) Both A and R are true, but R is not the correct explanation of A.
2. Assertion (A): Ordinary ocean waves are primarily caused by winds blowing across the water.
Reason (R): Ocean waves carry energy across the oceans over long distances.
Answer: (B) Both A and R are true, but R is not the correct explanation of A.
3. Assertion (A): Spring tides occur during the full Moon and new Moon.
Reason (R): During these phases, the Sun, Earth, and Moon are aligned, strengthening their combined gravitational effect on ocean water.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
4. Assertion (A): Neap tides have a smaller difference between high tide and low tide.
Reason (R): Neap tides occur during the first-quarter and third-quarter phases of the Moon.
Answer: (B) Both A and R are true, but R is not the correct explanation of A.
5. Assertion (A): High tides can help ships enter harbours more easily.
Reason (R): High tides raise the water level near the shore, providing greater water depth for ships.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
6. Assertion (A): The Gulf Stream helps keep Norwegian waters relatively warm.
Reason (R): The Labrador Current carries cold water along the eastern coast of Canada.
Answer: (B) Both A and R are true, but R is not the correct explanation of A.
7. Assertion (A): Regions where warm and cold ocean currents meet are often important fishing grounds.
Reason (R): These waters are rich in nutrients that support a large variety of fish.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
8. Assertion (A): Early warning systems can help reduce the loss of human and animal lives during cyclones and tsunamis.
Reason (R): These systems detect hazards and provide timely warnings so that people can evacuate and take protective action.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
9. Assertion (A): A country’s Exclusive Economic Zone (EEZ) generally extends up to 200 nautical miles from its baseline.
Reason (R): A country has special rights to explore, exploit, and use resources in its EEZ, although it does not fully own or control those waters.
Answer: (B) Both A and R are true, but R is not the correct explanation of A.
10. Assertion (A): International maritime rules help protect marine environments and prevent collisions between ships.
Reason (R): COLREGs establish rules for preventing collisions at sea, while MARPOL aims to reduce pollution from ships.
Answer: (A) Both A and R are true, and R is the correct explanation of A.
