Which of the following statements regarding cyclones and anti-cyclones is/are correct ? 1. In the Northern Hemisphere, cyclones rotate counter clockwise and anticyclones rotate clockwise. 2. Cyclones are often associated with cloudy or rainy weather, whereas anticyclones are often associated with fair weather. 3. In the Southern Hemisphere, the cyclonic spiral will be clockwise because the Coriolis force acts to the left. Select the answer using the code given below :
- A.1 only
- B.1 and 2 only
- C.2 and 3 only
- D.1, 2 and 3
Correct answer
Explanation
The correct answer is D, 1, 2 and 3. All three statements follow from how the Coriolis force turns winds around low and high pressure. A cyclone is a low-pressure centre into which winds blow, and an anticyclone is a high-pressure centre from which winds blow out. The Coriolis force, caused by the Earth's rotation, deflects moving air to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. So in the north, cyclones turn counter-clockwise and anticyclones clockwise, and in the south the pattern is reversed, with cyclones turning clockwise. In a cyclone, air converges and rises, cools and condenses, bringing clouds and rain. In an anticyclone, air sinks and warms, so skies stay clear and the weather is fair. Option A is wrong because it leaves out statements 2 and 3, which are also correct. Option B is wrong because it leaves out statement 3. Option C is wrong because it leaves out statement 1. Exam tip: north, low pressure, anticlockwise; south, low pressure, clockwise.
Practice Questions
View allWhich one of the following is not a minor plate ?
- A.Cocos Plate
- B.Nazca Plate
- C.Caroline Plate
- D.Antarctic Plate
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The Antarctic Plate, carrying Antarctica and the ocean around it, is one of the seven major lithospheric plates. Plate tectonics divides the lithosphere into seven major plates and several minor ones.
Read the full explanation →Which of the following statements with reference to shadow zones in an event of an earthquake is/are correct ? 1. Zone between 105° and 145° from epicentre was identified as the shadow zone for both P-waves and S-waves 2. The shadow zone of P-waves is much larger than that of the S-waves Select the answer using the code given below:
- A.1 only
- B.2 only
- C.Both 1 and 2
- D.Neither 1 nor 2
Show answer
The band between 105° and 145° from the epicentre receives neither P-waves nor S-waves, but it is the S-wave shadow zone that is much larger, so statement 2 is wrong.
Read the full explanation →Which of the following statements about Ring of Fire is/are correct ? 1. It is a zone of convergence plate boundaries 2. It is an active seismic and volcanic zone 3. It is associated with deep trench Select the correct answer using the code given below :
- A.1 and 2 only
- B.2 and 3 only
- C.1 only
- D.1, 2 and 3
Show answer
The Ring of Fire around the Pacific is a belt of convergent plate boundaries, full of active volcanoes and earthquakes and lined by deep ocean trenches.
Read the full explanation →Which one of the following rivers is not a tributary of river Brahmaputra ?
- A.River Manas
- B.River Kameng
- C.River Mahananda
- D.River Subansiri
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The Mahananda rises in the Darjeeling hills, flows through north Bengal and Bihar and joins the Ganga, not the Brahmaputra.
Read the full explanation →Which of the following statements regarding tropical cyclones is/are correct ? 1. These storms develop during the summer and autumn in every tropical ocean except the South Atlantic and eastern South Pacific Oceans. 2. Tropical cyclones that occur in the North Atlantic and eastern North Pacific Oceans are known as typhoons. 3. Tropical cyclones that occur in the Indian and South Pacific Oceans are called cyclones. Select the answer using the code given below :
- A.3 only
- B.1 and 2 only
- C.1 and 3 only
- D.1, 2 and 3
Show answer
Tropical cyclones of the North Atlantic and eastern North Pacific are called hurricanes, not typhoons, so statement 2 is wrong.
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