Which state shares the longest boundary with Rajasthan?

The correct answer is A, Odisha. The Tropic of Cancer lies at 23 degrees 30 minutes north and crosses eight Indian states: Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura and Mizoram. Odisha is not one of them, because the whole of the state lies south of that parallel, its northern edge reaching only about 22 degrees 34 minutes north.

Option B, Jharkhand, is crossed in its Ranchi plateau belt, so it is one of the eight. Option C, Mizoram, is the easternmost of the eight states the line touches. Option D, Rajasthan, is crossed at its southern tip in Banswara district near Kushalgarh, which is the fact this chapter asks for; because the line only clips that corner, almost all of Rajasthan lies in the sub-tropical zone. Candidates who remember that Odisha is a tropical coastal state pick it as a state on the line, which is the trap here.

The correct answer is D, 342,239 square kilometres. Rajasthan covers 342,239 square kilometres, about 10.4 per cent of the area of India, and it has been the largest state of the country since Madhya Pradesh was divided and Chhattisgarh created in November 2000. The state stretches about 826 kilometres from north to south and about 869 kilometres from east to west.

Option A, 240,928 square kilometres, is the area of Uttar Pradesh, the fourth largest state. Option B, 307,713 square kilometres, is the area of Maharashtra, the third largest. Option C, 308,245 square kilometres, is the area of Madhya Pradesh, which stands second and is the figure most often confused with Rajasthan in a hurry. Remembering the order Rajasthan, Madhya Pradesh, Maharashtra and Uttar Pradesh for area, against Uttar Pradesh first for population, settles a whole family of questions.

The correct answer is B, 23 degrees 3 minutes north to 30 degrees 12 minutes north. Rajasthan lies between these parallels and between 69 degrees 30 minutes east and 78 degrees 17 minutes east longitude, which places the whole state in the north-western, sub-tropical part of India, with only its southern tip in Banswara touching the Tropic of Cancer.

Option A moves the state too far south, into the latitudes of Maharashtra and Telangana. Option C, 21 degrees 6 minutes north to 26 degrees 30 minutes north, is the latitudinal extent of Madhya Pradesh and is the favourite distractor in state papers, because both states share the Tropic of Cancer story. Option D pushes the northern limit to 32 degrees north, which lies in Jammu and Kashmir and beyond Rajasthan altogether. Fix the easy pair, 23 degrees in the south and 30 degrees in the north, and the question is quick marks.

The correct answer is C, Banswara. The Tropic of Cancer touches Rajasthan only at its southern extremity and crosses Banswara district near Kushalgarh. This is why the state is described as lying almost wholly in the sub-tropical zone, even though it is often grouped with the tropical states of western India.

Option A, Udaipur, lies north of the line, in the Aravalli and Mewar country. Option B, Dungarpur, is the district next to Banswara in the same Vagad region and is the closest distractor; the line runs just south of it. Option D, Sirohi, lies further west and holds Guru Shikhar, the highest peak of the Aravalli, but not the Tropic of Cancer. The pairing worth memorising is Banswara for the Tropic of Cancer and Sirohi for Guru Shikhar, since papers often put the two districts in the same set of options.

The correct answer is A, Sirohi. Guru Shikhar rises to 1,722 metres on the Abu hills, an outlying block of the Aravalli in Sirohi district, and is the highest point both of Rajasthan and of the whole Aravalli system. Ser and Delwara, the next highest peaks, stand on the same hills.

Option B, Udaipur, holds the Bhorat plateau between Kumbhalgarh and Gogunda, which is high ground but lower than Abu. Option C, Ajmer, has Taragarh hill, a well known fort hill in the middle Aravalli, and is the usual trap for candidates who recall that the range is broadest near Ajmer. Option D, Alwar, lies in the north-eastern Aravalli where the range has broken into low detached hills, so its summits are modest. Remember the chain Guru Shikhar 1,722 m, Sirohi, Abu hills, and the related fact that the range runs about 692 kilometres in all.