Phalgu, a sacred river flowing in Bihar, is formed by the confluence of which of the following rivers?

The correct answer is B, Puducherry with its units at Puducherry, Karaikal, Mahe, and Yanam. Puducherry is the only Union Territory spread over both coasts of India. Puducherry and Karaikal lie on the east coast within Tamil Nadu, Yanam lies on the east coast in Andhra Pradesh, and Mahe lies on the west (Malabar) coast within Kerala. All four were French settlements; they came to India in 1954 and formally became part of India in 1962. Option A is wrong because the Andaman and Nicobar Islands lie only in the Bay of Bengal, on the eastern side. Option C is wrong because Lakshadweep lies only in the Arabian Sea, off the Kerala coast. Option D is wrong because Dadra and Nagar Haveli and Daman and Diu lie only on the western side, near Gujarat and Maharashtra. Exam tip: Puducherry has four districts in three states: Puducherry and Karaikal (Tamil Nadu), Yanam (Andhra Pradesh) and Mahe (Kerala).

The correct answer is A, Central Highlands. The Narmada divides the Peninsular plateau into two parts: the Central Highlands to its north and the Deccan Plateau to its south. The Central Highlands cover a major area of the Malwa plateau, with the Aravalli range to the north-west and the Vindhya range along the south. Rivers here, such as the Chambal, Sind, Betwa and Ken, flow from south-west to north-east, which shows the slope of the land. The eastward extensions of the Central Highlands are called Bundelkhand and Baghelkhand, and the Chotanagpur plateau lies further east. Option B is wrong because the Western Ghats mark the western edge of the Deccan Plateau, along the Arabian Sea coast. Option C is wrong because the Eastern Ghats form the broken eastern edge of the Deccan Plateau. Option D is wrong because the Deccan Plateau is the triangular landmass that lies south of the Narmada. Exam tip: north of the Narmada lie the Central Highlands; south of it lies the Deccan Plateau.

The correct answer is D, Granite. Granite forms when magma cools slowly deep inside the Earth's crust, so it is an intrusive or plutonic igneous rock. Slow cooling gives the minerals time to grow, which is why granite shows large, clearly visible grains of quartz, feldspar and mica. It is hard and long-lasting, so it is widely used in buildings, monuments and kitchen tops. Option A is wrong because sandstone is a sedimentary rock made of sand grains pressed and cemented together; the Red Fort in Delhi is built of red sandstone. Option B is wrong because slate is a metamorphic rock formed when shale is changed by heat and pressure. Option C is wrong because basalt is an extrusive igneous rock: lava cools quickly on the surface, giving fine grains, and the Deccan Traps are made of basalt. Exam tip: intrusive means it cools inside, slowly, with big crystals (granite); extrusive means it cools outside, fast, with fine grains (basalt).

The correct answer is C, Kali and Teesta. The Himalayas, about 2,400 km long, are divided from west to east into regions marked by river valleys, and the Nepal Himalayas lie between the Kali in the west and the Teesta in the east. This is the highest stretch of the whole range and holds Mount Everest as well as Kanchenjunga on the Nepal–Sikkim border. The Kali forms the border between Uttarakhand and Nepal, and the Teesta flows through Sikkim before entering West Bengal. Option A is wrong because the Sutlej and the Dihang together cover almost the whole range and do not mark any single section. Option B is wrong because the land between the Sutlej and the Kali is the Kumaon Himalayas. Option D is wrong because the land between the Teesta and the Dihang is the Assam Himalayas. West of the Sutlej, up to the Indus, lie the Punjab Himalayas, also called the Kashmir and Himachal Himalayas. Exam tip: Indus–Sutlej Punjab, Sutlej–Kali Kumaon, Kali–Teesta Nepal, Teesta–Dihang Assam.

The correct answer is C, Hindan. The Hindan rises in the Saharanpur district of Uttar Pradesh, flows south past Ghaziabad and joins the Yamuna near Greater Noida, on its left bank. The Yamuna is the longest tributary of the Ganga; it rises at the Yamunotri glacier and meets the Ganga at Prayagraj. Its left-bank tributaries, such as the Hindan, the Rind and the Sengar, come from the plains between the Yamuna and the Ganga. Its right-bank tributaries come from the south, from the Malwa plateau and Bundelkhand. Option A is wrong because the Chambal, which flows through the ravines of Madhya Pradesh and Rajasthan, joins the Yamuna from the right. Option B is wrong because the Ken, which flows through Panna in Madhya Pradesh, is a right-bank tributary. Option D is wrong because the Betwa, rising near Bhopal, also joins the Yamuna from the right, near Hamirpur. Exam tip: Yamuna right bank: Chambal, Sind, Betwa, Ken; left bank: Hindan, Rind, Sengar.