Which one of the following statements about earthquake waves is not correct?
- A.P waves move faster and are the first to arrive at the surface.
- B.P waves can travel through gaseous, liquid and solid materials.
- C.Seismographs located beyond 145° from epicentre can record the arrival of P waves.
- D.P waves have maximum area covered under its shadow zone.
Correct answer
D. P waves have maximum area covered under its shadow zone.
Explanation
The correct answer is D, because the largest shadow zone belongs to the S waves, not the P waves. S waves are transverse and cannot pass through the liquid outer core, so a wide belt beyond about 103 degrees from the epicentre receives no S waves at all. P waves, being longitudinal, are only bent by the core, and they reappear beyond about 145 degrees, which leaves them a narrower shadow zone between 103 and 145 degrees. The other three statements are correct and therefore not the answer. Option A is true because P waves are the fastest and reach a seismograph first, which is how they got the name primary waves. Option B is true because longitudinal waves pass through solids, liquids and gases alike. Option C is true because stations beyond 145 degrees do record P waves. Exam tip: P waves travel through all media with a shadow zone from 103 to 145 degrees, while S waves need solids and are absent beyond 103 degrees.
Practice Questions
View allMatch List-I to List-II and select the correct answer. List - I (Grassland) List - II (Location) (a) Campos (i) Australia (b) Pampas (ii) Venezuela (c) Down (iii) Argentina (d) Llanos (iv) Brazil
- A.(a) - (iv), (b) - (iii), (c) - (i), (d) - (ii)
- B.(a) - (iii), (b) - (ii), (c) - (iv), (d) - (i)
- C.(a) - (ii), (b) - (i), (c) - (iii), (d) - (iv)
- D.(a) - (i), (b) - (iv), (c) - (ii), (d) - (iii)
Show answer
Correct answer: A. (a) - (iv), (b) - (iii), (c) - (i), (d) - (ii)
Explanation
The correct answer is A, (a) - (iv), (b) - (iii), (c) - (i), (d) - (ii). The Campos are the tropical grasslands of the Brazilian highlands, the Pampas are the temperate grasslands of Argentina, the Downs are the temperate grasslands of south-east Australia, and the Llanos are the tropical grasslands of the Orinoco basin in Venezuela and Colombia. Grasslands carry a different local name in each region, and papers test these pairs: the Prairies in North America, the Steppes in Central Asia, the Veld in South Africa and the Canterbury plains in New Zealand. The Pampas are known for wheat and cattle and the Downs for sheep and wool. B, C and D are wrong because each of them shifts at least two of these names to the wrong continent, for example placing the Campos in Argentina or the Downs in Brazil. Exam tip: split them by climate - Campos and Llanos are tropical in South America, Pampas, Downs, Prairies, Steppes and Veld are temperate.
Which of the following river rises in the Indian Himalayan?
- A.Kosi
- B.Yamuna
- C.Gandak
- D.Ghaghra
Show answer
Correct answer: B. Yamuna
Explanation
The correct answer is B, Yamuna. The Yamuna rises from the Yamunotri glacier on the Bandarpunch range in the Uttarkashi district of Uttarakhand, so its source lies inside the Indian Himalayas. It is the longest tributary of the Ganga and joins it at Prayagraj, picking up the Chambal, Sind, Betwa and Ken on the way. The other three rivers in the question are also Ganga tributaries, but all of them begin outside India and enter the plains through Nepal. A is wrong because the Kosi is formed by the Sun Kosi, Arun and Tamur, which rise in Tibet and Nepal. C is wrong because the Gandak, called the Narayani in Nepal, rises near the Tibet-Nepal border. D is wrong because the Ghaghra rises as the Karnali in the Tibetan plateau near Mapchachungo. Exam tip: group them - Kosi, Gandak and Ghaghra come through Nepal, while the Yamuna begins at Yamunotri in Uttarakhand.
Which of the following hill stations do NOT experience snowfall in winters?
- A.Ooty
- B.Nainital
- C.Shimla
- D.Srinagar
Show answer
Correct answer: A. Ooty
Explanation
The correct answer is A, Ooty. Ooty, or Udhagamandalam, sits in the Nilgiri hills of Tamil Nadu at about 2,240 metres, but it lies close to the equator at roughly 11 degrees north, so its winter temperatures stay above freezing and it gets no snowfall. What it does get is heavy winter dew and occasional frost on the ground. Snowfall in India needs both height and a location far enough north for winter western disturbances to bring cold air and moisture, which is why the snow line runs along the Himalayas and not the southern hills. B is wrong because Nainital in the Kumaon Himalayas of Uttarakhand receives winter snow. C is wrong because Shimla in Himachal Pradesh is a well-known snowfall destination in December and January. D is wrong because Srinagar in the Kashmir valley sees regular and heavy snowfall. Exam tip: remember the reason - the Nilgiris are high but tropical, so Ooty gets frost, not snow.
In which of the following states is the Kolleru Lake located?
- A.Tamil Nadu
- B.Madhya Pradesh
- C.Kerala
- D.Andhra Pradesh
Show answer
Correct answer: D. Andhra Pradesh
Explanation
The correct answer is D, Andhra Pradesh. Kolleru Lake lies in Andhra Pradesh, between the deltas of the Krishna and the Godavari, spread across the Eluru and West Godavari districts. It is one of the largest freshwater lakes in India and is fed by the Budameru and Tammileru streams, draining into the Bay of Bengal through the Upputeru. The lake is a Ramsar site and was declared a wildlife sanctuary for the thousands of migratory birds, including grey pelicans, that winter there. A is wrong because Tamil Nadu has Pulicat, a brackish lagoon it shares with Andhra Pradesh. B is wrong because Madhya Pradesh is known for the Bhoj wetland at Bhopal, which is a man-made lake system. C is wrong because Kerala has the backwater lakes of Vembanad and Ashtamudi. Exam tip: remember the pair - Kolleru is a freshwater Ramsar lake between the Krishna and Godavari deltas in Andhra Pradesh.
Which of the following Indian states receive rainfall during October and November due to the North-East monsoon?
- A.Uttar Pradesh
- B.Maharashtra
- C.Madhya Pradesh
- D.Tamil Nadu
Show answer
Correct answer: D. Tamil Nadu
Explanation
The correct answer is D, Tamil Nadu. Tamil Nadu gets most of its rain from the north-east monsoon between October and December, which is why its rainy season comes when the rest of India is drying out. As the south-west monsoon withdraws, the winds reverse and blow from land to sea. Crossing the Bay of Bengal, these dry north-east winds pick up moisture and strike the Coromandel coast, giving Tamil Nadu a second and larger rainy spell. This is called the retreating monsoon or the post-monsoon season. A is wrong because Uttar Pradesh receives its rain from the south-west monsoon between June and September. B is wrong because Maharashtra is watered by the Arabian Sea branch of the south-west monsoon. C is wrong because Madhya Pradesh too depends on the south-west monsoon in the same June to September months. Exam tip: remember the exception - Tamil Nadu and the Coromandel coast are wettest in October to December.