Oceanography Questions and Answers

Q: To generate tidal power, the tidal range should be .......... meters and the basin should have considerable size.

The tidal range should be more than 5 metres.A tidal power station traps water in a basin at high tide and lets it out through turbines at low tide. The energy available depends on the square of the tidal range, so only sites with a large range, generally above about 5 m, and a large enclosable basin are economical. La Rance in France (range up to about 13 m) and the Gulf of Kachchh and Gulf of Khambhat in India are examples.Ranges of 1-4 m produce too little head to make a tidal barrage worthwhile.

Q: Which one of the following is tide dominated delta ?

The tide-dominated delta is the Ganga-Brahmaputra.Deltas are classed as river-, wave- or tide-dominated according to the process that shapes them. The Ganga-Brahmaputra delta faces a large tidal range in the Bay of Bengal, and tidal currents have cut its seaward part into many funnel-shaped channels separated by elongated islands, as in the Sundarbans, the typical form of a tide-dominated delta.The Mississippi is the standard river-dominated (bird's-foot) delta, while the Rhone and the Sao Francisco are wave-dominated deltas with smooth, cuspate shorelines.

Q: Which one of the following is an initial form of the sea wave ?

The initial form of a sea wave is the capillary wave.When wind begins to blow over calm water, it first raises tiny ripples less than about 1.7 cm long. Their restoring force is the surface tension of the water, so they are called capillary waves. As the wind continues, the ripples grow, and once they are longer, gravity becomes the restoring force and they become gravity waves.Gravity waves are the later, larger stage, infragravity waves are long-period waves such as surf beat, and 'ultragravity' is not the term for the first stage of wave growth.

Q: According to 'Ekman Spiral' the net transport of the water moves at .......... angle.

The net Ekman transport is at 90° to the wind.Wind drags the surface water, and the Coriolis force deflects it, so the surface current flows at about 45° to the wind. Each deeper layer moves more slowly and is deflected further, forming the Ekman spiral. Averaged over the whole wind-driven layer, the net transport of water is at right angles to the wind: to the right in the northern hemisphere and to the left in the southern.45° is the angle of the surface current only, and 60° and 75° are not the angles of net transport.

Q: Which is the true statement ?1. Ocean atmosphere coupling of water, heat and momentum transfer is also influenced by earth's rotation.2. The Coriolis force draws ocean water to the right of its path in the northern hemisphere.3. Moon and Sun creates tidal bulges on either side of earth.

All three statements are true, so the answer is 1, 2 and 3.Statement 1: the exchange of heat, water and momentum between ocean and atmosphere drives winds and currents, and the earth's rotation shapes both through the Coriolis effect. Statement 2: in the northern hemisphere the Coriolis force deflects moving water to the right of its path (to the left in the southern hemisphere). Statement 3: the tide-producing forces of the moon and sun raise two tidal bulges, one facing the attracting body and one on the opposite side of the earth.Since every statement is true, the options that leave any of them out are incomplete.

Q: As per the concept of ocean basin development, the stage of ocean basin closure is referred as .......... .

The stage of ocean basin closure is the terminal stage.In the Wilson cycle of ocean basin development, an ocean opens by rifting (embryonic stage, like the East African Rift), becomes a narrow sea (juvenile, like the Red Sea), widens into a full ocean (mature, like the Atlantic), then shrinks as subduction consumes its floor (declining, like the Pacific), reaches the terminal stage as it closes (like the Mediterranean), and finally disappears as continents collide (suturing, like the Himalaya).The mature and juvenile stages describe growing oceans, and 'old stage' is not the term used for closure.

Q: An average angle of continental slope is about .......... .

The average angle of the continental slope is about 4°.The continental slope runs from the shelf break, usually at about 130-200 m depth, down to the continental rise or the deep ocean floor. Although it looks steep on exaggerated profiles, its average gradient is only about 4°, ranging from 1° to 5° in most places and steeper along some faulted margins. It is still much steeper than the continental shelf, whose average slope is about 0.1°.Angles of 6° to 10° occur only on unusual slopes and are not the average.

Q: Converging long shore currents form .......... .

Converging longshore currents form rip currents.Where two longshore currents flowing along a beach from opposite directions meet, the water piled up near the shore has to return seaward. It does so as a narrow, fast rip current flowing out through the surf zone, which is why rip currents are dangerous to swimmers.Shore-normal and nearshore currents are general terms for the circulation of the surf zone, and tidal currents are driven by the tides, not by converging longshore flows.

Q: The high flux of solar radiation at the tropical and subtropical ocean water is higher than .......... °C.

The surface water in these regions is warmer than 25 °C.The tropical and subtropical oceans receive the highest flux of solar radiation on earth, because the sun is high in the sky throughout the year. As a result their surface waters are usually above 25 °C and in the warm pools of the western Pacific and Indian Oceans reach 28-30 °C, which is also why tropical cyclones form there.20, 15 and 10 °C are typical of subtropical-to-temperate and cooler waters, well below tropical surface temperatures.

41.

To generate tidal power, the tidal range should be .......... meters and the basin should have considerable size.

A.1-2
B.2-3
C.3-4
D.\(\gt 5\)

Exam Year(s)

MH SET - 2020, SET Exam - 2020,

Answer: D

The tidal range should be more than 5 metres.

A tidal power station traps water in a basin at high tide and lets it out through turbines at low tide. The energy available depends on the square of the tidal range, so only sites with a large range, generally above about 5 m, and a large enclosable basin are economical. La Rance in France (range up to about 13 m) and the Gulf of Kachchh and Gulf of Khambhat in India are examples.

Ranges of 1-4 m produce too little head to make a tidal barrage worthwhile.

Discuss in Forum

42.

Which one of the following is tide dominated delta ?

A.Ganga-Brahmaputra
B.Mississippi
C.Rhone
D.Sao Francisco

Exam Year(s)

MH SET - 2020, SET Exam - 2020,

Answer: A

The tide-dominated delta is the Ganga-Brahmaputra.

Deltas are classed as river-, wave- or tide-dominated according to the process that shapes them. The Ganga-Brahmaputra delta faces a large tidal range in the Bay of Bengal, and tidal currents have cut its seaward part into many funnel-shaped channels separated by elongated islands, as in the Sundarbans, the typical form of a tide-dominated delta.

The Mississippi is the standard river-dominated (bird's-foot) delta, while the Rhone and the Sao Francisco are wave-dominated deltas with smooth, cuspate shorelines.

Discuss in Forum

43.

Assertion (A) : Celestial bodies are responsible for the rhythmic change in the ocean water level.
Reason (R) : Centrifugal force created due to earth's revolution is responsible for the change in ocean water levels.

Which one of the following is correct ?

A.Both (A) and (R) are true and (R) is the correct explanation of (A)
B.Both (A) and (R) are true but (R) is not the correct explanation of (A)
C.(A) is true but (R) is false
D.(A) is false but (R) is true

Exam Year(s)

MH SET - 2020, SET Exam - 2020,

Answer: B

Both (A) and (R) are true but (R) is not the correct explanation of (A).

Tides, the rhythmic rise and fall of sea level, are caused mainly by the gravitational pull of the moon and, to a lesser extent, the sun, so the assertion is true.

The reason is also true in that a centrifugal effect, arising from the revolution of the earth-moon system about its common centre, helps raise the tidal bulge on the side of the earth away from the moon. But it is only a component of the mechanism; the cause the assertion refers to is the attraction of the celestial bodies, so R is not the explanation of A.

Discuss in Forum

44.

Which one of the following is an initial form of the sea wave ?

A.Infragravity
B.Gravity
C.Ultragravity
D.Capillary wave

Exam Year(s)

MH SET - 2020, SET Exam - 2020,

Answer: D

The initial form of a sea wave is the capillary wave.

When wind begins to blow over calm water, it first raises tiny ripples less than about 1.7 cm long. Their restoring force is the surface tension of the water, so they are called capillary waves. As the wind continues, the ripples grow, and once they are longer, gravity becomes the restoring force and they become gravity waves.

Gravity waves are the later, larger stage, infragravity waves are long-period waves such as surf beat, and 'ultragravity' is not the term for the first stage of wave growth.

Discuss in Forum

45.

According to 'Ekman Spiral' the net transport of the water moves at .......... angle.

A.45°
B.60°
C.90°
D.75°

Exam Year(s)

MH SET - 2020, SET Exam - 2020,

Answer: C

The net Ekman transport is at 90° to the wind.

Wind drags the surface water, and the Coriolis force deflects it, so the surface current flows at about 45° to the wind. Each deeper layer moves more slowly and is deflected further, forming the Ekman spiral. Averaged over the whole wind-driven layer, the net transport of water is at right angles to the wind: to the right in the northern hemisphere and to the left in the southern.

45° is the angle of the surface current only, and 60° and 75° are not the angles of net transport.

Discuss in Forum

46.

Which is the true statement ?

1. Ocean atmosphere coupling of water, heat and momentum transfer is also influenced by earth's rotation.
2. The Coriolis force draws ocean water to the right of its path in the northern hemisphere.
3. Moon and Sun creates tidal bulges on either side of earth.

A.Only 1
B.2 and 3
C.1 and 3
D.1, 2 and 3

Exam Year(s)

MH SET - 2020, SET Exam - 2020,

Answer: D

All three statements are true, so the answer is 1, 2 and 3.

Statement 1: the exchange of heat, water and momentum between ocean and atmosphere drives winds and currents, and the earth's rotation shapes both through the Coriolis effect. Statement 2: in the northern hemisphere the Coriolis force deflects moving water to the right of its path (to the left in the southern hemisphere). Statement 3: the tide-producing forces of the moon and sun raise two tidal bulges, one facing the attracting body and one on the opposite side of the earth.

Since every statement is true, the options that leave any of them out are incomplete.

Discuss in Forum

47.

As per the concept of ocean basin development, the stage of ocean basin closure is referred as .......... .

A.Mature stage
B.Juvenile stage
C.Old stage
D.Terminal stage

Exam Year(s)

MH SET - 2020, SET Exam - 2020,

Answer: D

The stage of ocean basin closure is the terminal stage.

In the Wilson cycle of ocean basin development, an ocean opens by rifting (embryonic stage, like the East African Rift), becomes a narrow sea (juvenile, like the Red Sea), widens into a full ocean (mature, like the Atlantic), then shrinks as subduction consumes its floor (declining, like the Pacific), reaches the terminal stage as it closes (like the Mediterranean), and finally disappears as continents collide (suturing, like the Himalaya).

The mature and juvenile stages describe growing oceans, and 'old stage' is not the term used for closure.

Discuss in Forum

48.

An average angle of continental slope is about .......... .

A.10°
B.8°
C.6°
D.4°

Exam Year(s)

MH SET - 2020, SET Exam - 2020,

Answer: D

The average angle of the continental slope is about 4°.

The continental slope runs from the shelf break, usually at about 130-200 m depth, down to the continental rise or the deep ocean floor. Although it looks steep on exaggerated profiles, its average gradient is only about 4°, ranging from 1° to 5° in most places and steeper along some faulted margins. It is still much steeper than the continental shelf, whose average slope is about 0.1°.

Angles of 6° to 10° occur only on unusual slopes and are not the average.

Discuss in Forum

49.

Converging long shore currents form .......... .

A.Shore normal currents
B.Rip currents
C.Near shore currents
D.Tidal currents

Exam Year(s)

MH SET - 2020, SET Exam - 2020,

Answer: B

Converging longshore currents form rip currents.

Where two longshore currents flowing along a beach from opposite directions meet, the water piled up near the shore has to return seaward. It does so as a narrow, fast rip current flowing out through the surf zone, which is why rip currents are dangerous to swimmers.

Shore-normal and nearshore currents are general terms for the circulation of the surf zone, and tidal currents are driven by the tides, not by converging longshore flows.

Discuss in Forum

50.

The high flux of solar radiation at the tropical and subtropical ocean water is higher than .......... °C.

A.25
B.20
C.15
D.10

Exam Year(s)

MH SET - 2020, SET Exam - 2020,

Answer: A

The surface water in these regions is warmer than 25 °C.

The tropical and subtropical oceans receive the highest flux of solar radiation on earth, because the sun is high in the sky throughout the year. As a result their surface waters are usually above 25 °C and in the warm pools of the western Pacific and Indian Oceans reach 28-30 °C, which is also why tropical cyclones form there.

20, 15 and 10 °C are typical of subtropical-to-temperate and cooler waters, well below tropical surface temperatures.

Oceanography Questions and Answers

Topics

Other Subjects

Tags: Oceanography Questions and Answers

About Us

Oceanography Questions and Answers

Topics

Other Subjects

Tags: Oceanography Questions and Answers

About Us

Stay informed about all important Dates & Notifications