Which of the following statements is true?
- (a)Tide comes on the earth every day after exactly 12 hours 30 minutes.
- (b)Benguela current is a cold current of the Pacific Ocean.
- (c)Ocean salinity is maximum at the Tropic of Cancer and Capricorn.
- (d)If the Sun, the Earth and the Moon are in a straight line then this situation is the situation of small tide.
Correct — C. Surface ocean salinity is highest in the subtropical belts around the Tropics of Cancer (23.5°N) and Capricorn (23.5°S). These are zones of high-pressure, descending dry air with very high evaporation and low rainfall, so more water leaves as vapour than is added — concentrating the salts. (At the equator heavy rain and river inflow dilute the water, and near the poles low evaporation plus ice-melt keep salinity low.)
- (a)Tide comes on the earth every day after exactly 12 hours 30 minutes. — Two high tides occur in a lunar day of about 24 hours 50 minutes, so successive high tides are roughly 12 hours 25 minutes apart — not 'exactly 12 hours 30 minutes'; the figure and the word 'exactly' are wrong.
- (b)Benguela current is a cold current of the Pacific Ocean. — The Benguela is a cold current of the ATLANTIC Ocean, flowing north along the south-west coast of Africa (Namibia/South Africa) — not the Pacific.
- (d)If the Sun, the Earth and the Moon are in a straight line then this situation is the situation of small tide. — When the Sun, Earth and Moon are aligned (new/full moon), their gravitational pulls add up to give SPRING tides — the highest tides, not small ones. Small (neap) tides occur when the Sun and Moon are at right angles.
This 'pick the true statement' item bundles three ocean topics — tides, ocean currents and salinity. Surface salinity varies with latitude: it peaks in the subtropical high-pressure belts (near the Tropics) where evaporation greatly exceeds precipitation, and falls at the equator (rain/rivers) and the poles (low evaporation, ice-melt). Average ocean salinity is about 35 parts per thousand.
Eliminate the false statements using standard geography: the tidal interval is ~12h25m in a ~24h50m lunar day (not 12h30m); the Benguela is an Atlantic (not Pacific) cold current; alignment of Sun-Earth-Moon gives spring (large) tides, not small ones. That leaves the salinity statement as the only true one.
- Highest surface salinity: subtropical belts near the Tropics of Cancer & Capricorn (high evaporation, low rainfall).
- Lunar day ≈ 24h50m; two high tides ⇒ successive high tides ~12h25m apart.
- Benguela current = a COLD current of the Atlantic Ocean (SW coast of Africa).
- Spring tide (highest) at new/full moon when Sun-Earth-Moon align; neap tide (small) at quadrature.
Salinity peaks near the Tropics of Cancer and Capricorn — the correct statement.
- Mixing up the tidal interval (12h25m) and the lunar day (24h50m); the '12h30m, exactly' phrasing is a trap.
- Placing the Benguela current in the wrong ocean, or calling Sun-Earth-Moon alignment a 'small' (neap) tide instead of a spring tide.
UPPSC/UPSC combine tides, currents and salinity in a single 'which statement is correct' item — check each clause against the standard rule.
No directly related past PYQ was found.
- practice — not a real PYQ
The Benguela cold current flows along the coast of which continent?
- (a)South-west Africa
- (b)Western South America
- (c)Eastern Australia
- (d)Western Europe
Answer(a) South-west Africa — the Benguela is a cold current of the Atlantic Ocean off Namibia/South Africa.
- practice — not a real PYQ
Spring tides (the highest tides) occur when the Sun, the Earth and the Moon are:
- (a)At right angles to one another
- (b)In a straight line (new or full moon)
- (c)At the equinoxes only
- (d)Farthest apart
Answer(b) In a straight line at new or full moon — the pulls add up to give the highest tides.