Due to attraction of the sun and the moon, what is the frequency of up and falls down of ocean water in a day?
- A.Two
- B.Three
- C.Four
- D.One
Correct answer
Explanation
The correct answer is A, Two. Because of the gravitational pull of the moon and the sun, together with the centrifugal effect of the earth's rotation, most coasts see the sea rise and fall twice in a day. The moon's pull raises a bulge of water on the side of the earth facing it and another on the opposite side, and as the earth turns a place passes through both bulges in about twenty-four hours. These are called semi-diurnal tides, and successive high tides come about twelve hours and twenty-five minutes apart. Option B is wrong because no shore gets three tidal cycles in a day. Option C is wrong because four counts the individual tides — two high and two low — while the rise-and-fall cycle itself happens twice. Option D is wrong because a single daily high and low, called a diurnal tide, occurs only on a few coasts such as parts of the Gulf of Mexico. Exam tip: spring tides come at full moon and new moon when sun and moon pull in line, and neap tides at the quarters.
Practice Questions
View allWhere is Hambantota Port located?
- A.Iran
- B.Sri Lanka
- C.Japan
- D.Pakistan
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Hambantota Port lies on the southern coast of Sri Lanka, close to the main shipping lanes of the Indian Ocean.
Read the full explanation →Which of the following statements is/are correct? 1. Himalayan rivers have their origin in the snow-covered areas, hence are dry in winter season. 2. Rivers of the Peninsular Plateau have reached maturity. 3. Himalayan rivers depict all the three stages of normal cycle of erosion. Select the correct answer using the code given below.
- A.2 only
- B.1 and 3 only
- C.2 and 3 only
- D.1, 2 and 3
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Himalayan rivers are perennial, so statement 1 is wrong, while statements 2 and 3 are correct. Himalayan rivers such as the Ganga, Indus and Brahmaputra rise from glaciers and snowfields and also get monsoon rain, so they flow all year round, including in winter.
Read the full explanation →Which of the following statements related to latitude are true? 1. Rainfall, temperature and vegetation vary with latitude. 2. The difference between the longest day and the shortest day increases with latitude. 3. Indira Point is located approximately at 6°45' N latitude. Select the correct answer using the code given below.
- A.1 and 2 only
- B.1 and 3 only
- C.2 and 3 only
- D.1, 2 and 3
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All three statements about latitude are true. Latitude decides how directly the Sun's rays strike a place, so temperature, rainfall and the type of vegetation change from the equator towards the poles, from hot, wet rainforests to cold tundra.
Read the full explanation →Which of the following lakes is/are situated in Ladakh? 1. Tso Kar 2. Pangong Tso 3. Tsomgo 4. Tso Moriri Select the correct answer using the code given below.
- A.1 only
- B.2 and 3
- C.1, 2 and 4
- D.2 and 4 only
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Tso Kar, Pangong Tso and Tso Moriri are high-altitude lakes of Ladakh, while Tsomgo lies in Sikkim. Pangong Tso, at about 4,350 metres, is a long, narrow lake that stretches from Ladakh into Tibet, and most of its length lies on the Chinese side.
Read the full explanation →Damanganga Reservoir Project with about 115 km of minor canals and distributaries is located in
- A.NCT
- B.Dadra and Nagar Haveli
- C.Puducherry
- D.Goa
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The Damanganga Reservoir Project is the main irrigation scheme of Dadra and Nagar Haveli, whose canal network of about 115 km of minor canals and distributaries serves the territory.
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