IAS Prelims Exam: Physical Geography NCERT Questions: MOVEMENTS OF OCEAN WATER Set II

Q1. Durgaduani, sunderbans is
a. First ever tidal power plant in sunderbans 
b.   It is a creek, which connects the Bidyadhari and Gomdirivers.
c. First ever UNESCO Tiger reserve 
d. Both a and b

Answer: d

Explanation: With a generation capacity of 3. 6 mw, the project will comprise two barrages built across the upstream and downstream ends of the Durgaduani creek, which runs between the islands of Gosaba and Bali-Bijayanagar and connects the Bidyadhari and Gomdi rivers.

Q2. Which of the following is/are primary forces which initiate the movement of water?
1. Coriolis force
2. Gravity
3. Heating by solar energy

Select the correct answer from the following codes
a.    Only 1
b.    Only 1 and 2
c.    Only 2 and 3
d.    1,2 and 3

Answer: d

Explanation: Ocean currents are influenced by two types of forces namely: (i) primary forces that initiate the movement of water; (ii) secondary forces that influence the currents to flow. The primary forces that influence the currents are: (i) heating by solar energy; (ii) wind; (iii) gravity; (iv) coriolis force.

Q3. Consider the following statements 
1. Ocean water in equator is in higher level than at middle latitudes
2. Movement of water body is affected by friction between wind and water surface.

Select the correct answer from the following codes
a. Only 1
b. Only 2
c. Both 1 and 2
d. Neither 1 nor 2

Answer: c

Explanation: Heating by solar energy causes the water to expand. That is why, near the equator the ocean water is about 8 cm higher in level than in the middle latitudes. Friction between the wind and the water surface affects the movement of the water body in its course. Gravity tends to pull the water down to pile and create gradient variation. The Coriolis force intervenes and causes the water to move to the right in the northern hemisphere and to the left in the southern hemisphere.

Q4. Consider the following statements 
1. Half of the water in the ocean constitutes surface water.
2. In the northern hemisphere warm currents are found on the west coasts of continents in high latitudes.

Select the correct answer from the following codes
a. Only 1
b. Only 2
c. Both 1 and 2
d. Neither 1 nor 2

Answer: b

Explanation: surface currents constitute about 10 per cent of all the water in the ocean, these waters are the upper 400 m of the ocean; deep water currents make up the other 90 per cent of the ocean water. Warm currents bring warm water into cold water areas and are usually observed on the east coast of continents in the low and middle latitudes (true in both hemispheres). In the northern hemisphere they are found on the west coasts of continents in high latitudes.

Q5.Major ocean currents are influenced by which of the following factors?
1. prevailing winds
2.  coriolis force
3. Distribution of land

Select the correct answer from the following codes
a.    Only 1
b.    Only 1 and 2
c.    Only 2 and 3
d.    1,2 and 3

Answer: b

Explanation: Major ocean currents are greatly influenced by the stresses exerted by the prevailing winds and Coriolis force. The oceanic circulation pattern roughly corresponds to the earth’s atmospheric circulation pattern.

Q6. Consider the following statements 
1.  Oceanic circulation pattern follow cyclonic and anti cyclonic air circulation pattern.
2. The air circulation over the oceans in the middle latitudes is mainly cyclonic.

Select the correct answer from the following codes
a. Only 1
b. Only 2
c. Both 1 and 2
d. Neither 1 nor 2

Answer: a

Explanation: The air circulation over the oceans in the middle latitudes is mainly anticyclonic (more pronounced in the southern hemisphere than in the northern hemisphere). The oceanic circulation pattern also corresponds with the same. At higher latitudes, where the wind flow is mostly cyclonic, the oceanic circulation follows this pattern. In regions of pronounced monsoonal flow, the monsoon winds influence the current movements.

Q7. Which of the following is/are characteristics of ocean current?
1.  Currents are slow at surface compared to depths
2. A current is usually strongest at the surface and decreases in strength with depth.
3. Speed of the current is referred to as Drift.

Select the correct answer from the following codes
a.    Only 1
b.    Only 1 and 2
c.    Only 2 and 3
d.    1,2 and 3

Answer: c

Explanation: We refer to the speed of a current as its “drift.” Drift is measured in terms of knots. The strength of a current refers to the speed of the current. A fast current is considered strong. A current is usually strongest at the surface and decreases in strength (speed) with depth. Most currents have speeds less than or equal to 5 knots.

Q8. Consider the following statements 
1.  Similar to atmospheric circulation, oceanic circulation transport heat from one place to other.
2. Zone of mixing of warm and cold currents are worlds best fishing grounds.

Select the correct answer from the following codes
a. Only 1
b. Only 2
c. Both 1 and 2
d. Neither 1 nor 2

Answer: c

Explanation: The oceanic circulation transports heat from one latitude belt to another in a manner similar to the heat transported by the general circulation of the atmosphere. The mixing of warm and cold currents help to replenish the oxygen and favour the growth of planktons also the primary food for fish population. The best fishing grounds of the world exist mainly in these mixing zones.