1. Coral reefs require certain specific conditions to survive in the best manner.

Which of the following is correct with regard to these conditions?

(a) Water temperature must be below 10°C.

(b) Shallow water is not favourable.

(c) They will not survive where there are cold currents.

(d) Clear, oxygenated water hamper their development.

Answer: (c) Explanation: A coral reef is an underwater ecosystem characterized by reef- building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups. Option (a) is incorrect. Corals generally live in water temperatures of 20–32° C. Option (b) is incorrect. Shallow water is favourable as at greater depths sunlight is too faint for photosynthesis. Option (c) is correct. They do not survive where there are cold currents as there will be upwelling of the cold water from the depths. Option (d) is incorrect. Clear, oxygenated water promote their development.

2. The terms ‘Titli’ and ‘Luban’ have been in the news recently. What are these?

(a) Titli is a genetically modified rice variety whereas Luban is a genetically modified cotton variety.

(b) Titli is a genetically modified cotton variety whereas Luban is a genetically modified rice variety.

(c) Titli is a cyclonic storm originating in the Bay of Bengal whereas Luban is a cyclonic storm originating in the Arabian Sea.

(d) Titli is a cyclonic storm originating in the Arabian Sea whereas Luban is a cyclonic storm originating in the Bay of Bengal.

Answer: (c) Explanation: The India Meteorological Department (IMD) called the formation of the two very severe cyclones—Titli (over the Bay of Bengal) and Luban (over the Arabian Sea)—on two sides of the Indian mainland as ‘rarest of rare’ occurrences. The IMD also said the movement of both these storms was unique. While Titli changed its direction and moved towards the northeast after making a landfall, Luban too kept going in different directions over the 9 days that it travelled through the south-eastern Arabian Sea towards Yemen and Oman on the Gulf coast and then made landfall on October 13.

3. Consider the following statements about ‘Iron ore’:

(1) China is the largest producer of iron ore in the world.

(2) Hematite, Magnetite, Limonite and Siderite are the four varieties of iron ore.

(3) Jharkhand is one of the major iron ore producing state in India.

Which of the statements given above is/are correct?

(a) 1 only

(b) 1 and 2 only

(c) 1 and 3 only

(d) 1, 2 and 3

Answer: (d) Explanation: Statement (a) is correct. China is the largest producer of iron ore in the world. Most of it is consumed within country only for domestic use. Statement (b) is correct. There are four varieties of iron ore - Hematite, Magnetite, Limonite and Siderite.

Statement (c) is correct. The major iron ore producing states in India are Jharkhand, Karnataka, Odisha and Chhattisgarh. Goa, Maharashtra, Andhra Pradesh and Tamil Nadu are minor producers. The main exporting nations are Brazil, Australia, Canada and India. These four countries together account for about 70% of total export of iron ore.

4. Match List-I with List-II and select the correct answer using the code given below the lists:

List-I (Resource) (Location)

A. Lead 1. Jharia

B. Coal 2. Zawar Mines

C. Petroleum Oil 3. Sambalpur

D. Bauxite 4. Digboi

Codes

A B C D

(a) 2 1 4 3

(b) 3 4 2 1

(c) 3 4 1 2

(d) 2 1 3 4

Answer: (a) Explanation: In India, lead production comes from the Zawar mines of Rajasthan and Arcot district of Tamil Nadu. Coal lie in Jharkhand-Bengal coal belt and the important coal fields in this region are Raniganj, Jharia, Bokaro, Giridih and Karanpura. The major oil producing areas are Digboi, Ankaleshwar, Mumbai high, Kalol. Odisha happens to be the largest producer of bauxite. Sambalpur and Kalahandi are the leading producers of bauxite.

5. With reference to ‘Nuclear Energy Resources’, consider the following statements:

(1) Thorium is mainly obtained from monazite and ilmenite.

(2) World’s richest monazite deposits occur in Maharashtra.

Which of the statements given above is/are incorrect?

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

Answer: (b)

Explanation: Statement (1) is correct. Thorium is mainly obtained from monazite and ilmenite in the beach sands along the coast of Kerala and Tamil Nadu. Statement (2) is incorrect. World’s richest monazite deposits occur in Palakkad and Kollam districts of Kerala, Vishakhapatnam in Andhra Pradesh and Mahanadi river delta of Odisha.