Longitude, Meridians, and Local Time

The governing concept is Earth’s rotation and the relation between longitude and local time. Earth rotates from west to east, so places lying farther east turn toward the Sun earlier than places farther west. Consequently, the eastern parts of India experience sunrise before the western parts, even though the country uses one standard time. A difference in longitude produces a difference in local solar time; roughly, 1° of longitude corresponds to 4 minutes. Option A is therefore correct. The other choices do not explain the time difference: India is not divided into northern and southern hemispheres for this reason, the Sun rises everywhere on the sunlit side, and being near the sea has no direct role.

The governing concept is the relationship between longitude and local solar time. Earth rotates from west to east, so places located farther east generally experience sunrise and noon earlier than places farther west. Since India extends considerably from west to east, the local time calculated from the Sun differs across the country. Every 1° of longitude represents approximately 4 minutes of time, so a large longitudinal span can produce a substantial time difference. India therefore uses 82°30′ E as a common standard meridian to maintain one official time. Option A is correct; latitude affects climatic zones, while soil colour, river direction, and mountain height are not direct effects of longitude.

The governing rule is that local solar time changes with longitude: each degree of longitude corresponds to approximately four minutes of time. India extends about 29° from west to east, so the theoretical difference is 29 × 4 = 116 minutes, or about 1 hour 56 minutes. This is conventionally described as roughly two hours. The east experiences sunrise and local noon earlier than the west, although the whole country follows Indian Standard Time based on 82°30′ E. Option B is correct because it identifies the longitudinal extent and supports the calculation. Latitude mainly influences climate, not this east–west time difference; the Equator and island status are irrelevant.

The governing concept is Earth's west-to-east rotation and the resulting relationship between longitude and local solar time. As Earth rotates, eastern places turn toward the Sun before western places. Therefore, for two Indian locations on the same general date, the place with the more easterly longitude will generally experience sunrise earlier and its local solar time will be ahead. This does not mean every clock in the country shows a different official time, because India follows one standard time based on 82°30′ E. Option B is correct. Clouds or relief can affect visible conditions, but they do not change the basic longitude principle.

The governing concept is the coordinate system of latitude and longitude. Latitude measures angular distance north or south of the Equator and is written with N or S. Longitude measures angular distance east or west of the Prime Meridian and is written with E or W. Thus the directional suffix or phrase is the safest first clue: north–south means latitude, while east–west means longitude. Option A is correct. Option B is unreliable because a number may represent an area, distance or coordinate. Options C and D confuse units or symbols with coordinate types; percentages and kilometres do not automatically identify longitude or latitude. Context and direction must be checked together.

Longitude measures a place’s position east or west of the Prime Meridian (0°). Because Earth rotates, local time also differs with longitude; therefore, option A is correct. North-south position is measured by latitude, not longitude. Exam tip: a difference of 1° in longitude corresponds to about 4 minutes of time.