The Kaimur plateau of Bihar lies mainly in which districts?

The correct answer is C, 94,163 square kilometres. Bihar covers 94,163 square kilometres, which makes it the twelfth largest state of India by area, although it stands third in population after Uttar Pradesh and Maharashtra. The state lost a large share of its old area when the plateau districts became Jharkhand in November 2000.

Option A, 79,716 square kilometres, is the area of Jharkhand, the state carved out of Bihar, and is the most tempting wrong answer for that reason. Option B, 88,752 square kilometres, is close to the area of Himachal Pradesh and is offered only as a near figure. Option D, 135,192 square kilometres, is the area of Chhattisgarh. The pair worth memorising together is Bihar 94,163 square kilometres and Jharkhand 79,716 square kilometres, because questions often ask which of the two is larger.

The correct answer is C, 24 degrees 20 minutes north to 27 degrees 31 minutes north. Stated exactly, Bihar lies between 24 degrees 20 minutes 10 seconds north and 27 degrees 31 minutes 15 seconds north latitude, and between 83 degrees 19 minutes 50 seconds east and 88 degrees 17 minutes 40 seconds east longitude. Because its southern edge is above 23 degrees 30 minutes north, the Tropic of Cancer does not pass through the state.

Option A, 21 degrees 6 minutes to 26 degrees 30 minutes north, is the latitudinal extent of Madhya Pradesh. Option B, 23 degrees 52 minutes to 30 degrees 24 minutes north, is the extent of Uttar Pradesh, the neighbour to the west, and is the commonest wrong choice in Bihar papers. Option D, 27 degrees 39 minutes to 30 degrees 55 minutes north, is the extent of Haryana. Remember Bihar as a narrow band between roughly 24 and 27 and a half degrees north, only about 345 kilometres from north to south.

The correct answer is B, Nepal. Bihar has an international boundary of about 726 kilometres with Nepal along its entire northern edge, and the rivers that make north Bihar fertile and flood-prone, the Gandak, Bagmati, Kamla Balan and Kosi, all cross that boundary into the state.

Option A, Bhutan, borders Sikkim, West Bengal, Assam and Arunachal Pradesh, and West Bengal lies between it and Bihar. Option C, Bangladesh, borders West Bengal, Assam, Meghalaya, Tripura and Mizoram; the narrow Siliguri corridor of West Bengal separates it from Bihar, so candidates who picture eastern India roughly often choose it. Option D, Myanmar, borders Arunachal Pradesh, Nagaland, Manipur and Mizoram, far to the east. Bihar's other three neighbours are all Indian states: Uttar Pradesh in the west, Jharkhand in the south and West Bengal in the east.

The correct answer is C, Ganga. The Ganga enters Bihar near Chausa in Buxar district, flows from west to east for about 445 kilometres and leaves the state near Rajmahal. It splits the plain into the larger North Bihar plain and the narrower South Bihar plain, and almost every physical fact about the state is stated with reference to that line.

Option A, the Son, is the largest river of the south, flowing north to join the Ganga near Maner, but it drains only the south-western corner. Option B, the Gandak, is one of the Himalayan rivers of the north bank and meets the Ganga at Patna. Option D, the Kosi, is the most unstable of the northern rivers and is called the Sorrow of Bihar, but it too is a tributary and not the dividing line. The clean picture to carry into the exam is the Ganga running across the middle, Himalayan and perennial rivers joining from the north, plateau and seasonal rivers from the south.

The correct answer is A, Someshwar peak in West Champaran. The Someshwar hills form the narrow Shivalik belt in the extreme north-west of Bihar, with flat valleys called duns lying between the ridges, and Someshwar peak, about 880 metres, is the highest point of the state. It is the only genuinely hilly country Bihar kept after 2000.

Option B, the Rajgir hills of Nalanda, are low quartzite ridges rising out of the south Bihar plain and famous in history rather than for height. Option C, the Kharagpur hills of Munger, are an outlier of the Chhotanagpur plateau and also fall well short of Someshwar. Option D, the Kaimur hills of Rohtas, form the sandstone plateau fringe in the south-west with fine scarps and waterfalls, and they are the usual wrong answer because candidates associate height with plateau country. Keep the pairing Someshwar, West Champaran, about 880 metres.