Here are 25 MCQs on Oceanic Geography — ideal for NDA/CDS/AFCAT/General GK prep:
NDA & CDS 1 2026 Exam GK – Geography MCQ – Class 1
1. Which is the largest ocean in the world by surface area?
A. Indian Ocean
B. Atlantic Ocean
C. Pacific Ocean
D. Arctic Ocean
Answer: C
2. The deepest point in the world’s oceans is located in which trench?
A. Tonga Trench
B. Mariana Trench
C. Java Trench
D. Puerto Rico Trench
Answer: B
3. The term “salinity” in oceans refers to the concentration of:
A. Organic matter
B. Dissolved salts
C. Suspended sediments
D. Calcium carbonate
Answer: B
4. Which ocean has the highest average salinity?
A. Arctic Ocean
B. Indian Ocean
C. Atlantic Ocean
D. Southern Ocean
Answer: C
5. The boundary between two oceanic water masses with different temperatures is called:
A. Thermocline
B. Halocline
C. Pycnocline
D. Isopycnal
Answer: A
6. Which ocean current is the largest and strongest in the world?
A. Gulf Stream
B. Kuroshio Current
C. Antarctic Circumpolar Current
D. California Current
Answer: C
7. The “Ring of Fire” is located around which ocean?
A. Indian Ocean
B. Pacific Ocean
C. Atlantic Ocean
D. Arctic Ocean
Answer: B
8. Which type of tide occurs when the Sun, Moon, and Earth are aligned?
A. Neap Tide
B. Spring Tide
C. Low Tide
D. Diurnal Tide
Answer: B
9. The Sargasso Sea is located in which ocean?
A. Indian Ocean
B. Pacific Ocean
C. Southern Ocean
D. Atlantic Ocean
Answer: D
10. The warm ocean current off the eastern coast of the USA is called:
A. Labrador Current
B. California Current
C. Gulf Stream
D. Canary Current
Answer: C
11. The “Great Ocean Conveyor Belt” refers to:
A. Air circulation
B. Deep ocean circulation
C. Tidal movement
D. Sea-level rise
Answer: B
12. Which ocean is the smallest in size?
A. Arctic Ocean
B. Atlantic Ocean
C. Indian Ocean
D. Southern Ocean
Answer: A
13. The “El Niño” phenomenon originates in which ocean?
A. Indian Ocean
B. Atlantic Ocean
C. Pacific Ocean
D. Arctic Ocean
Answer: C
14. The main cause of ocean tides is:
A. Earth’s rotation
B. Gravitational pull of the Moon and Sun
C. Ocean temperature
D. Wind patterns
Answer: B
15. Underwater mountain chains in oceans are called:
A. Trenches
B. Ridges
C. Guyots
D. Atolls
Answer: B
16. The mid-ocean ridge system is longest in which ocean?
A. Pacific Ocean
B. Atlantic Ocean
C. Indian Ocean
D. Southern Ocean
Answer: B
17. The process of cold, nutrient-rich water rising to the surface is known as:
A. Downwelling
B. Upwelling
C. Convection
D. Subduction
Answer: B
18. Coral reefs are generally found in:
A. Cold water regions
B. Deep ocean basins
C. Warm shallow tropical seas
D. Polar regions
Answer: C
19. Which ocean current causes the cooling of Peru’s coast?
A. Humboldt Current
B. Gulf Stream
C. Kuroshio Current
D. Agulhas Current
Answer: A
20. The “Oceanic Dead Zones” are primarily caused by:
A. Volcanic eruptions
B. Excess nutrient pollution
C. Tidal variations
D. Seafloor spreading
Answer: B
21. The Southern Ocean surrounds which continent?
A. Africa
B. Australia
C. South America
D. Antarctica
Answer: D
22. The ratio of total dissolved solids in seawater to pure water is known as:
A. Density
B. Salinity
C. Turbidity
D. Conductivity
Answer: B
23. The “Indian Ocean Dipole (IOD)” influences the climate of:
A. Europe
B. Australia
C. South America
D. Canada
Answer: B
24. The longest trench in the Indian Ocean is:
A. Java Trench
B. Makran Trench
C. Diamantina Trench
D. Ninety East Ridge
Answer: A
25. The zone where sunlight does not reach in the ocean is called:
A. Photic zone
B. Subphotic zone
C. Aphotic zone
D. Pelagic zone
Answer: C
