Directions (1-15): Read the following passage carefully and answer the questions given below it. Certain words are given bold to help you to locate them while answering some of the questions.
Ocean currents are the vertical or horizontal movement of both surface and deep water throughout the world's oceans. Currents normally move in a specific direction and aid significantly in the circulation of the Earth's moisture, the resultant weather, and water pollution.
Oceanic currents are found all over the globe and vary in size, importance, and strength. Some of the more prominent currents include the California and Humboldt Currents in the Pacific, the Gulf Stream and Labrador Current in the Atlantic, and the Indian Monsoon Current in the Indian Ocean. These are just a sampling of the seventeen major surface currents found in the world's oceans.
In addition to their varying size and strength, ocean currents differ in type. They can be either surface or deep water.
Surface currents are those found in the upper 400 meters (1,300 feet) of the ocean and make up about 10% of all the water in the ocean. Surface currents are mostly caused by the wind because it creates friction as it moves over the water. This friction then forces the water to move in a spiral pattern, creating gyres. In the northern hemisphere, gyres move clockwise and in the southern they spin counterclockwise. The speed of surface currents is the greatest closer to the ocean's surface and decreases at about 100 meters (328 ft) below the surface.
Because surface currents travel over long distances, the Coriolis force also plays a role in their movement and deflects them, further aiding in the creation of their circular pattern. Finally, gravity plays a role in the movement of surface currents because the top of the ocean is uneven. Mounds in the water form in areas where the water meets land, where water is warmer, or where two currents converge. Gravity then pushes this water downslope on the mounds and creates currents.
Deep water currents, also called thermohaline circulation, are found below 400 meters and makeup about 90% of the ocean. Like surface currents, gravity plays a role in the creation of deep water currents but these are mainly caused by density differences in the water.
Density differences are a function of temperature and salinity. Warm water holds less salt than cold water so it is less dense and rises toward the surface while cold, salt-laden water sinks. As the warm water rises though, the cold water is forced to rise through up welling and fill the void left by the warm. By contrast, when the cold water rises, it too leaves a void and the rising warm water is then forced, through downwelling, to descend and fill this empty space, creating thermohaline circulation.
Thermohaline circulation is known as the Global Conveyor Belt because its circulation of warm and cold water acts as a submarine river and moves water throughout the ocean.
Finally, seafloor topography and the shape of the ocean's basins impact both surface and deep water currents as they restrict areas where water can move and "funnel" it into another.
Because ocean currents circulate water worldwide, they have a significant impact on the movement of energy and moisture between the oceans and the atmosphere. As a result, they are important to the world's weather. The Gulf Stream, for example, is a warm current that originates in the Gulf of Mexico and moves north toward Europe. Since it is full of warm water, the sea surface temperatures are warm, which keeps places like Europe warmer than other areas at similar latitudes.
The Humboldt Current is another example of a current that affects weather. When this cold current is normally present off the coast of Chile and Peru, it creates extremely productive waters and keeps the coast cool and northern Chile arid. However, when it becomes disrupted, Chile's climate is altered and it is believed that El Nino plays a role in its disturbance.
Like the movement of energy and moisture, debris can also get trapped and moved around the world via currents. This can be man-made which is significant to the formation of trash islands or natural such as iceberg. The Labrador Current, which flows south out of the Arctic Ocean along the coasts of Newfoundland and Nova Scotia, is famous for moving icebergs into shipping lanes in the North Atlantic.
Currents plan an important role in navigation as well. In addition to being able to avoid trash and icebergs, knowledge of currents is essential to the reduction of shipping costs and fuel consumption. Today, shipping companies and even sailing races often use currents to reduce time spent at sea.
Finally, ocean currents are important to the distribution of the world's sea life. Many species rely on currents to move them from one location to another whether it is for breeding or just simple movement over large areas.
Today, ocean currents are also gaining significance as a possible form of alternative energy. Because water is dense, it carries an enormous amount of energy that could possibly be captured and converted into a usable form through the use of water turbines. Currently, this is an experimental technology being tested by the United States, Japan, China, and some European Union countries.
Whether ocean currents are used as alternative energy, to reduce shipping costs, or in their nature to state to move species and weather worldwide, they are significant to geographers, meteorologists, and other scientists because they have a tremendousimpact on the globe and earth-atmosphere relations.
Q1. The ideas contained in the passage can be best summarized as:
A. (i) Ocean currents (ii) The types and causes of ocean currents (iii) The importance of Ocean currents (iv) Ocean Currents as alternative energy.
B. (i) Ocean currents (ii) Surface currents (iii) Deepwater currents (iv) Ocean currents as alternative energy.
C. (i) The types and causes of ocean currents (ii) Surface currents (iii) Deepwater currents (iv) Ocean currents as alternative energy.
D. (i) Surface currents (ii) Deepwater currents (iii) the importance of Ocean currents (iv) Ocean currents as alternative energy.
(a) A and D
(b) A only
(c) B and C
(d) B and D
(e) D only
S1. Ans.(b)
Sol. A only. The passage begins with an introduction (first and second paragraph) and analyses the types and causes of the currents (paragraphs 3 to 9), tells us the importance of these currents (paragraphs 10 to 14), and sums by talking about currents as alternative energy (the last two paragraphs). Compare this structure with the other options and you will see that they are wrong or incomplete.
Q2. It can be inferred from the passage that the direction of the movement of the gyres in the two hemispheres is opposite to each other because....
(a) the direction of the wind is in the opposite direction.
(b) the earth rotates on its axis.
(c) the earth is spherical in shape.
(d) the temperature of the oceans in the two hemispheres is different.
(e) the salinity of the oceans in the two hemispheres is different.
S2. Ans.(c)
Sol. The surface currents (gyres) are created by the winds. This is all that is stated in the passage; next, the passage states that the direction of the gyres in the two hemispheres is in the opposite direction (clockwise and anticlockwise). Nothing more is said about it. The only reason for the direction to change is the spherical shape of the earth. As we can imagine each hemisphere as an inversion of the other hemisphere, the direction naturally changes.
Q3. According to the passage, which of the following factors affect/s the movement of the surface currents?
A. Deflection due to the force of the earth’s rotation.
B. The temperature of the water.
C. Convergence of currents.
D. Friction of wind over water.
(a) A and D
(b) C and D
(c) B, C and D
(d) A, C and D
(e) All of the above
S3. Ans.(e)
Sol. All the factors are mentioned in the fourth and the fifth paragraphs as influencing the movement of the surface ocean currents. Coriolis is the deflection due to the force of the earth's spin.
Q4. According to the passage, which of the following is/are NOT TRUE about the deep water currents?
A. They hold less salt than surface currents.
B. These deep waters sink into the deep ocean basins at regions where the temperatures are cold enough to cause the density to increase.
C. They move water around the world.
D. Topography and shape of the land restrict their movement.
(a) A only
(b) A and D
(c) B only
(d) A, B, and D
(e) C only
S4. Ans.(b)
Sol. Statement A is the opposite of what is stated in the passage. Deep currents make up 90% of the ocean water-hence they hold more salt; their density is higher than surface currents (which are merely 10% of the ocean)-on this count also they hold more salt. Statements B and C are correct. D is incorrect because the passage states the topography of the ocean floor (not land) and the shape of the ocean basins affect them.
Sol. Statement A is the opposite of what is stated in the passage. Deep currents make up 90% of the ocean water-hence they hold more salt; their density is higher than surface currents (which are merely 10% of the ocean)-on this count also they hold more salt. Statements B and C are correct. D is incorrect because the passage states the topography of the ocean floor (not land) and the shape of the ocean basins affect them.
Q5. Which of the following can be inferred about the Humboldt Current?
(a) It is caused by "up welling."
(b) It is caused by "down welling."
(c) It is important to the world's weather.
(d) It keeps the South America cool.
(e) It keeps the South America warm.
S5. Ans.(a)
Sol. All that is said in the passage (the data available for the inference) is that Humboldt is a cold current. Earlier in the passage, it is stated that upwelling causes cold water to rise and warm water to go down ("... the cold water is forced to rise through upwelling...". From this data we can safely assume that Humboldt is caused by "upswelling".
Sol. All that is said in the passage (the data available for the inference) is that Humboldt is a cold current. Earlier in the passage, it is stated that upwelling causes cold water to rise and warm water to go down ("... the cold water is forced to rise through upwelling...". From this data we can safely assume that Humboldt is caused by "upswelling".
Q6. "When this cold current is normally present off the coast of Chile and Peru, it creates extremely productive waters and keeps the coast cool and northern Chile arid." In the context of the passage, the word productive corresponds to which of the following definitions?
(a) Having the power of producing; generative; creative.
(b) Producing readily or abundantly; fertile.
(c) Causing; bringing about.
(d) Producing or tending to produce goods and services having exchange value.
(e) Of or pertaining to the language skills of speaking and writing.
S6. Ans.(b)
Sol. Productive waters would mean waters in which marine life would thrive. Hence option (b) which states 'fertile' would best correspond to the meaning required in the context.
Q7. According to the passage, the ocean currents do which of the following?
A. They circulate marine life and weather across the globe.
B. They circulate water worldwide.
C. They circulate water pollution.
D. They help the shipping industry.
(a) A and B
(b) A, B, and C
(c) B, C, and D
(d) All of the above
(e) None of the above
S7. Ans.(d)
Sol. All the statements can be found at different parts of the passage. Hence all are correct.
Sol. All the statements can be found at different parts of the passage. Hence all are correct.
Q8. Thermohaline circulations are found how many meters below?
(a)440
(b)90
(c)328
(d)400
(e)897
S8. Ans.(d)
Sol. 400 meters
Q9. Why thermohaline circulation is known as the Global Conveyor Belt?
(a)Many species rely on currents to move them from one location to another
(b)Whether ocean currents are used as alternative energy, to reduce shipping costs, or in their natural to state to move species and weather worldwide
(c)Currents normally move in a specific direction and aid significantly in the circulation of the Earth's moisture, the resultant weather, and water pollution.
(d)because its circulation of warm and cold water acts as a submarine river and moves water throughout the ocean.
(e)gravity plays a role in the creation of deep water currents but these are mainly caused by density differences in the water.
S9. Ans.(d)
Sol. because its circulation of warm and cold water acts as a submarine river and moves water throughout the ocean.
Sol. because its circulation of warm and cold water acts as a submarine river and moves water throughout the ocean.
Q10. According to the passage, Which of the following sentence given below is false?
(a). The speed of surface currents is the greatest closer to the ocean's surface and decreases at about 100 meters (328 ft) below the surface.
(b)Surface currents found in the upper 400 meters (1,300 feet) of the ocean.
(c)In the northern hemisphere, gyres move clockwise and in the southern they spin counterclockwise
(d)Surface currents make up about 10% of all the water in the ocean.
(e) Gulf Stream is a cold current that originates in the Gulf of Mexico and moves north toward Europe
S10. Ans.(e)
Sol.
Q11. Which of the following is most nearly similar in meaning of the word prominent as used in the passage?
(a)criticized
(b)serious
(c)eminent
(d)promises
(e)undistinguished
S11. Ans.(c)
Sol. Prominent- important; famous, projecting from something; protuberant.
synonyms-important, well known, leading, eminent, pre-eminent
Q12. Which of the following is most nearly similar in meaning of the word gyres as used in the passage?
(a)hike
(b)whirl
(c)gaffe
(d)weapons
(e)acute
S12. Ans.(b)
Sol. gyres -whirl or gyrate.
Sol. gyres -whirl or gyrate.
Q13.Which of the following is most Opposite in meaning of the word mounds as used in the passage?
(a)flip
(b)outlandish
(c)pile
(d)ditch
(e)pluralistic
S13. Ans.(d)
Sol. mounds-a rounded mass projecting above a surface, a large pile or quantity of something.
Sol. mounds-a rounded mass projecting above a surface, a large pile or quantity of something.
Q14. Which of the following is most Opposite in meaning of the word welling as used in the passage?
(a)drainage
(b)conclusion
(c)gush
(d)efflux
(e)oozing
S14. Ans.(b)
Sol. welling-(of a liquid) rise up to the surface and spill or be about to spill,(of an emotion) develop and become more intense.
Synonyms- flow, stream, run, rush, gush, course, roll, cascade, flood, surge
Sol. welling-(of a liquid) rise up to the surface and spill or be about to spill,(of an emotion) develop and become more intense.
Synonyms- flow, stream, run, rush, gush, course, roll, cascade, flood, surge
Q15. Which of the following is most Opposite in meaning of the word tremendous as used in the passage?
(a)vast
(b)astounding
(c)monumental
(d)miniature
(e)colossal
S15. Ans.(d)
Sol. tremendous-very great in amount, scale, or intensity, extremely good or impressive; excellent.
synonyms- very great, huge, enormous, immense, colossal, massive, prodigious, stupendous, monumental, mammoth, vast, gigantic, giant, mighty, epic
