On which plateau, the Tropic of Cancer and the Indian Standard Time Line intersect each other?

Question

UnlockIAS · Accepted Answer

Correct — B, Baghelkhand. Two lines are named and each has an exact value you can put on a map. The Tropic of Cancer is the parallel of 23°26′ N — the northern limit of the overhead Sun, rounded to 23°30′ in most textbooks. The Indian Standard Time line is the meridian of 82°30′ E, chosen because 82.5 ÷ 15 gives IST its clean UTC+05:30 offset, and it is the meridian conventionally said to pass through Mirzapur in Uttar Pradesh. Their intersection is therefore a single point at roughly 23°26′ N, 82°30′ E, and that point falls in Sonhat tahsil of Koriya district in northern Chhattisgarh — the Koriya upland that forms the south-eastern shoulder of the Baghelkhand plateau.

The safer exam route reaches the same place without pinpointing anything, because only one of the three plateaus offered extends far enough east. Follow the IST meridian south from Mirzapur (25°09′ N, 82°30′ E): it leaves Uttar Pradesh at about 24°40′ N, runs the whole length of Singrauli district in eastern Madhya Pradesh, and crosses into Koriya district of Chhattisgarh near 23°48′ N — Baghelkhand country the entire way. Sonbhadra and Sidhi are often put on this list and neither belongs: Sonbhadra lies east of the meridian and Sidhi west of Singrauli, so the line passes between them. Now run the Tropic of Cancer eastward: at about 75°48′ E it is in Ujjain district in the heart of Malwa, at 77° E in Shajapur, at 78°30′ E in Raisen, at 80° E in Jabalpur, at 81° E in Umaria — a Baghelkhand district — and at 82° E in Manendragarh-Chirimiri-Bharatpur in northern Chhattisgarh. The two traverses converge in one region only.

The asymmetry between the two lines is worth carrying on its own, because it is what makes the question answerable. The Tropic of Cancer crosses eight states; the IST meridian crosses five — Uttar Pradesh, Madhya Pradesh, Chhattisgarh, Odisha and Andhra Pradesh — going Mirzapur, Singrauli, Koriya, Janjgir-Champa, Mahasamund, Gariaband, Nabarangapur, Koraput, Alluri Sitharama Raju and Kakinada before it leaves the coast into the Bay of Bengal near 17° N. It touches neither Jharkhand nor West Bengal, both of which the Tropic does cross. The two lists overlap in exactly two states, Madhya Pradesh and Chhattisgarh, so the crossing has to be in one of them; it falls in Chhattisgarh, in Koriya, roughly 40 km south of the Madhya Pradesh border.

Where the medium confidence sits: no official document publishes "the plateau on which the Tropic and the IST line cross". The crossing itself lies in Koriya, and the cultural region of Baghelkhand, defined by Bagheli speech and usually listed as Rewa, Satna, Sidhi, Singrauli, Shahdol, Umaria, Anuppur, Maihar and Mauganj in Madhya Pradesh with Sonbhadra and Chitrakoot in Uttar Pradesh, does not formally include a Chhattisgarh district. Physiographically the same plateau continues south-east into Koriya and Surguja, and a question that asks about a plateau is asking for the physiographic reading. On that reading (b) is secure, and it has no rival: Bundelkhand's eastern edge is more than 150 km west of the crossing, and Malwa's Tropic crossing near Ujjain is close to 700 km west.

Why the other options are wrong — (a) Bundelkhand lies roughly between 78° and 81° E and 24° and 26° N — Jhansi, Lalitpur, Jalaun, Hamirpur, Mahoba and Banda in Uttar Pradesh, Datia, Tikamgarh, Chhatarpur, Panna, Sagar and Damoh in Madhya Pradesh — and it fails on both coordinates at once. Its eastern edge stops well short of 82°30′ E, and it sits almost wholly north of 23°26′ N, so the Tropic never enters it: carry the Tropic east at Bundelkhand's own longitude of 78°30′ E and you are in Raisen district, south of the region altogether. This is the trap for the candidate who files Bundelkhand under "central Indian plateau" without ever fixing it on a grid.  (c) Malwa is the volcanic upland of west-central Madhya Pradesh and south-eastern Rajasthan, north of the Vindhya Range, averaging about 500 m and drained by the Mahi, the Chambal and the headwaters of the Betwa. Its meridians run about 74° to 78° E. The Tropic of Cancer genuinely does cross it — through Ujjain district, near 75°48′ E — and Ujjain's association with the Tropic is well enough known to make this option feel right. But the IST meridian is roughly 700 km further east; the two lines cannot meet anywhere in Malwa.  (d) This would be correct only if the crossing fell outside all three plateaus, and it does not. At 23°26′ N, 82°30′ E the point lies in the Koriya upland of northern Chhattisgarh — the south-eastern continuation of the same plateau that carries the IST meridian down from Mirzapur through Singrauli. The only ground for choosing (d) is to insist on the narrow cultural definition of Baghelkhand as a Bagheli-speaking district list, which is not what a question about a plateau is asking for.

Concept: Two of the most heavily used reference lines on any map of India are one parallel and one meridian, and both have values worth memorising to the minute. The Tropic of Cancer is 23°26′ N, the latitude at which the Sun stands overhead at the June solstice and the northern boundary of the tropics; Indian textbooks conventionally round it to 23°30′. It crosses eight states, west to east: Gujarat, Rajasthan, Madhya Pradesh, Chhattisgarh, Jharkhand, West Bengal, Tripura and Mizoram. The Indian Standard Time line is 82°30′ E, adopted because it converts to an exact 5 hours 30 minutes ahead of Greenwich, and it is identified with Mirzapur in Uttar Pradesh. The three plateaus in the options all belong to the Central Highlands, the northern block of the Peninsular plateau, and they lie in a west-to-east row: Malwa, a Deccan-basalt upland averaging about 500 m; Bundelkhand, an ancient granite and gneiss surface between the Yamuna and the Vindhyas; and Baghelkhand in the east, limestone and sandstone in its western part and granite in the east, threaded in the north by the Son — the river that gives Sonbhadra district its name.

State PCS 2023 Q98 — Geography PYQ with Answer

State PCS 2023 Q98 — Geography PYQ with Answer