Chapter 12: Water Oceans — Online MCQ Test
GEOGRAPHY · Grade 11 · CBSE(NCERT)
Practice Chapter 12: Water Oceans with a free chapter-wise online MCQ test.
This chapter covers: Oceans hydrosphere ocean distribution salinity ocean temperature marine environment climate regulation water resources.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter 12: Water Oceans — Important Questions & Answers
Which is the largest ocean on Earth?
- A. Indian Ocean
- B. Atlantic Ocean
- C. Pacific Ocean
- D. Arctic Ocean
Answer: C. Pacific Ocean
The Pacific Ocean is the largest ocean by area and volume. It covers about one-third of the Earth's surface.
The Pacific Ocean is the largest ocean by area and volume. It covers about one-third of the Earth's surface.
What is the average salinity of ocean water?
- A. 3.5%
- B. 35%
- C. 0.35%
- D. 0.035%
Answer: A. 3.5%
The average salinity of ocean water is about 35 parts per thousand, which is equivalent to 3.5%.
The average salinity of ocean water is about 35 parts per thousand, which is equivalent to 3.5%.
Why is salinity generally higher in tropical and subtropical oceans than near the equator?
- A. Because rainfall is lower and evaporation is higher
- B. Because ocean currents stop near the tropics
- C. Because rivers carry no water there
- D. Because the Sun does not heat these regions
Answer: A. Because rainfall is lower and evaporation is higher
High evaporation and low rainfall in tropical and subtropical belts tend to increase salinity. Near the equator, heavy rainfall usually lowers salinity.
High evaporation and low rainfall in tropical and subtropical belts tend to increase salinity. Near the equator, heavy rainfall usually lowers salinity.
Which statement correctly describes the relationship between ocean and climate?
- A. Oceans have no role in climate regulation
- B. Oceans store and redistribute heat, affecting global climate
- C. Only continents regulate climate, not oceans
- D. Oceans influence climate only through salinity
Answer: B. Oceans store and redistribute heat, affecting global climate
Oceans absorb, store, and release large amounts of heat, which helps regulate climate. They also influence humidity, rainfall, and winds.
Oceans absorb, store, and release large amounts of heat, which helps regulate climate. They also influence humidity, rainfall, and winds.
Which of the following is the most accurate reason why the Antarctic Ocean water is cold despite receiving sunlight during summer?
- A. It has no contact with the atmosphere
- B. The Sun’s rays are completely blocked by clouds all year
- C. Low angle of incidence and ice cover limit heating
- D. Antarctic water contains no dissolved salts
Answer: C. Low angle of incidence and ice cover limit heating
At high latitudes, sunlight arrives at a low angle and is less effective in heating. Sea ice also reflects much of the incoming solar radiation.
At high latitudes, sunlight arrives at a low angle and is less effective in heating. Sea ice also reflects much of the incoming solar radiation.