Which of the following is/are warm ocean current(s)? 1. Alaska Current 2. Agulhas Current 3. Falkland Current 4. West Australian Current Select the answer using the code given below:
- (a)1 only
- (b)1 and 2
- (c)3 and 4
- (d)4 only
Correct — B, the Alaska and Agulhas Currents. The Alaska Current is a warm current that carries tropical-origin water polewards along the north-west coast of North America into the Gulf of Alaska, and the Agulhas Current is the warm western-boundary current of the southern Indian Ocean that flows down the east coast of southern Africa. Both move warm water away from the tropics, so both are warm. The Falkland (Malvinas) Current and the West Australian Current, by contrast, carry cold water towards the equator and are cold currents, which rules out every code except 1 and 2.
- (a)1 only — The Alaska Current is indeed warm, but this code drops the Agulhas Current, which is also a warm current, so it is incomplete.
- (c)3 and 4 — This is the mirror-image trap — the Falkland Current and the West Australian Current are the two cold currents in the list, not the warm ones.
- (d)4 only — The West Australian Current is a cold, equatorward eastern-boundary current off the west coast of Australia, not a warm current.
Ocean currents are broad, wind-driven surface flows that redistribute heat around the globe. A warm current moves warmer water from lower latitudes towards the poles, while a cold current moves colder water from higher latitudes towards the equator. As a rule of thumb, warm currents hug the east coasts of continents (the western sides of ocean basins) and cold currents hug the west coasts (the eastern sides of ocean basins).
Sorting the four currents needs only the warm-versus-cold rule. The Alaska and Agulhas Currents are poleward-flowing western-boundary currents and are warm; the Falkland and West Australian Currents flow equatorwards and are cold. Option (c) is tempting because it groups the two Southern-Hemisphere-sounding names, but it actually lists the two cold currents — the exact opposite of what is asked.
- Warm currents carry water polewards, usually along the east coasts of continents; cold currents carry water equatorwards, usually along the west coasts.
- The Alaska Current is warm and flows into the Gulf of Alaska along north-west North America.
- The Agulhas Current is the warm western-boundary current of the southern Indian Ocean, off south-east Africa.
- The Falkland (Malvinas) Current and the West Australian Current are both cold currents.
Only the Alaska and Agulhas Currents are warm, so the answer is 1 and 2 (option B); the Falkland and West Australian Currents are cold.
- Do not assume a current is cold just because its name sounds southern — the Agulhas is warm.
- Option (c) lists exactly the two cold currents, the negation of the warm ones asked for.
Asked to pick the warm (or cold) currents from a numbered list, or to classify a named current as warm or cold.
What could be the main reason/reasons for the formation of African and Eurasian desert belt? 1. It is located in the sub-tropical high pressure cells. 2. It is under the influence of warm ocean currents. Which of the statements given above is/are correct in this context?
- (a) 1 only
- (b) 2 only
- (c) Both 1 and 2
- (d) Neither 1 nor 2
Answer(a) 1 only — the deserts lie under sub-tropical high pressure; the coasts are washed by cold, not warm, currents.
Turns on the same warm-versus-cold current distinction — statement 2 is wrong precisely because those coasts carry cold currents, the very classification this NDA item tests.
Which one among the following statements with reference to Benguela current is NOT correct?
- (a) It influences the climate of the West coast of North Africa
- (b) It is a cold current
- (c) Its direction is from South to North
- (d) It flows in the Atlantic Ocean
Answer(a) It influences the climate of the West coast of North Africa
Same warm/cold-current theme — there you confirm the Benguela is a cold current off south-west Africa; here you separate the two warm currents from the two cold ones.
- practice — not a real PYQ
Which one of the following is a cold ocean current?
- (a)Gulf Stream
- (b)Kuroshio Current
- (c)Benguela Current
- (d)Brazil Current
Answer(c) Benguela Current — a cold, equatorward eastern-boundary current off the south-west coast of Africa.
- practice — not a real PYQ
The warm Agulhas Current flows in which one of the following oceans?
- (a)Atlantic Ocean
- (b)Indian Ocean
- (c)Pacific Ocean
- (d)Arctic Ocean
Answer(b) Indian Ocean — the Agulhas is the warm western-boundary current of the southern Indian Ocean.