मुख्य सामग्री पर जाएं
REET Level 2 · Social Studies

Latitude and Longitude — REET Notes (Social Studies)

इसे हिंदी में पढ़ें →

Latitude and longitude are the basis for pinpointing any location on Earth and working out its local time. REET tests this topic with direct calculation-based questions on time using longitude, so both memorising the formula and applying it correctly matter.

  • 2 questions in REET 2024
  • Class 6 level
  • 10 min read
Verified 17 September 2026 · Source: NCERT Class 6 Social Science — Chapter 1: Locating Places on the Earth

How REET asks this topic

Both REET 2024 questions were direct calculations — one asked you to work out the time difference between two longitudes and state the correct local time (if it's 10 am at 15°E, what time is it at 75°E), the other asked for the distance between two longitude lines at the Equator (about 111 km). In other words, remembering the definitions alone isn't enough here — you also need to correctly apply formulas like '1° of longitude = 4 minutes' and '1° at the Equator ≈ 111 km'.

Lines of latitude

Definition
Angular distance north or south of the Equator (0°); counting up to the poles (90°N/90°S), a total of 181 latitude lines (including the Equator) are recognised.
Major latitude lines
Equator (0°), Tropic of Cancer (23.5°N), Tropic of Capricorn (23.5°S), Arctic Circle (66.5°N), Antarctic Circle (66.5°S).
Shape
Latitude lines are parallel circles to one another; the Equator is the largest circle, and their size keeps shrinking towards the poles, reducing to a single point at the poles.
Distance between two latitudes
Roughly constant, about 111 km everywhere (because latitude lines remain parallel to each other).

Lines of longitude

Definition
Angular distance east or west of the Prime Meridian (0°, Greenwich, London); a total of 360 longitude lines (180°E and 180°W together form a single line).
Shape
Longitude lines are semicircles that meet at both poles; the distance between them is greatest at the Equator (about 111 km) and shrinks to zero at the poles.
Relationship between time and longitude
Earth rotates 360° in 24 hours, meaning a time difference of 15° per hour and 4 minutes per 1° of longitude.
International Date Line
A line running roughly along the 180° longitude, drawn zigzag to avoid land areas; crossing it changes the date by one day.

Indian Standard Time (IST)

India's standard meridian is 82°30' East longitude, which passes near Mirzapur in Uttar Pradesh. Indian Standard Time (IST) is based on the local time of this line and runs 5 hours 30 minutes ahead of Greenwich Mean Time (GMT+5:30).

India's longitudinal extent runs roughly from 68°7'E to 97°25'E — a spread of about 30°, which means there's a difference of about 2 hours between the local time at the country's eastern and western edges. Even so, for administrative convenience, the entire country uses a single standard time (IST) so that rail traffic, communication and daily functioning stay uniform.

How to calculate time

The rule is simple: a place further east has a later (more advanced) time, and a place further west has an earlier (behind) time — because the Earth rotates from west to east, and the sun appears to rise earlier at places further east. In any calculation, first find the angular difference (in degrees) between the two longitudes, then multiply it by 4 minutes per degree to get the time difference in minutes, and finally add or subtract this from the base time according to direction (east = add, west = subtract).

Additional facts on latitude-longitude and India

Prime Meridian
0° longitude, which passes through the Greenwich Observatory in London; east and west longitude is measured from this line.
India's latitudinal extent
Roughly 8°4'N to 37°6'N — meaning India lies entirely in the Northern Hemisphere.
Total number of time zones (world)
The world is theoretically divided into 24 time zones (each 15° wide), though many countries adjust the boundaries for their own convenience.
Why a single standard time?
Even though India has a natural time difference of about 2 hours, it has adopted just one standard time (based on 82.5°E) for the whole country, for administrative and transport uniformity, rather than separate time zones.

How to teach this to children

Classroom activity (Class 6)

Have children draw latitude (horizontal circles) and longitude (vertical semicircles) lines on an orange or a ball with a marker — this makes the difference in shape between the two clearly visible.

Teaching aids

A globe of the world or a map of India, with the Tropic of Cancer, the standard meridian (82.5°E) and the Equator marked in different colours.

Common misconception

Children often confuse latitude and longitude — help them remember: latitude lines are horizontal ('lying down'), longitude lines are vertical.

Assessment idea

Give simple numerical examples (such as 'find the time difference at 30°E') and have children solve them both orally and in writing, to check practical application of the formula.

Memory trick / exam tip

'1° of longitude = 4 minutes' and 'east ahead, west behind' — these two facts solve every time-calculation question. For example: (75°−15°) × 4 minutes = 240 minutes = 4 hours, and since 75°E is further east than 15°E, add the time: 10 am + 4 hours = 2 pm.

REET 2024 questions asked (with solutions)

Question 147

If it is 10.00 AM at a place located at 15° east longitude, then what will be the time at a place located at 75° east longitude ?

  1. Aदोपहर 02.00
  2. Bसुबह 02.00
  3. Cरात्रि के 10.00
  4. Dसुबह 06.00

Explanation

प्रत्येक 1° देशान्तर पर समय में 4 मिनट का अन्तर होता है। 75° − 15° = 60°, इसलिए अन्तर = 60 × 4 = 240 मिनट = 4 घंटे। 75° पूर्व, 15° पूर्व से और पूर्व में है, अतः वहाँ समय आगे होगा: सुबह 10.00 + 4 घंटे = दोपहर 02.00 बजे।

Question 105

The distance between two meridians (1 interval) at equator is

  1. A109 किमी
  2. B119 किमी
  3. C55.4 किमी
  4. D111 किमी

Explanation

भूमध्य रेखा पर पृथ्वी की परिधि लगभग 40,075 किमी है, जिसे 360 देशान्तरों में बाँटने पर दो क्रमागत देशान्तर रेखाओं के बीच की दूरी लगभग 111 किमी (111.3 किमी) आती है। ध्रुवों की ओर जाने पर देशान्तर रेखाएँ पास आती जाती हैं और यह दूरी घटती जाती है तथा ध्रुवों पर शून्य हो जाती है।

Practice questions

Question 1

How many longitude lines are there in total on the Earth?

  1. A180
  2. B181
  3. C360
  4. D365

Explanation

Counting from 0° to 180°E and 0° to 180°W together gives a total of 360 longitude lines on Earth. The total number of latitude lines is 181 (0° to 90°N and 90°S, including the Equator).

Question 2

What is India's Standard Meridian?

  1. A68°7' पूर्व
  2. B82°30' पूर्व
  3. C97°25' पूर्व
  4. D0° (ग्रीनविच)

Explanation

India's standard meridian is 82°30' (82.5°) East longitude, which passes near Mirzapur in Uttar Pradesh, and Indian Standard Time (IST) is based on it.

Question 3

By how much is Indian Standard Time (IST) ahead of Greenwich Mean Time (GMT)?

  1. A4 घंटे 30 मिनट
  2. B5 घंटे
  3. C5 घंटे 30 मिनट
  4. D6 घंटे

Explanation

Indian Standard Time (IST) is 5 hours 30 minutes ahead of Greenwich Mean Time (GMT+5:30), because India's standard meridian lies at 82.5°E longitude.

Question 4

If it is 12 noon at 0° longitude (Greenwich), what will be the local time at 30° West longitude?

  1. Aदोपहर 2 बजे
  2. Bप्रातः 10 बजे
  3. Cदोपहर 12 बजे
  4. Dरात्रि 10 बजे

Explanation

30° × 4 minutes = 120 minutes = 2 hours. Since 30°W is west of Greenwich, the time there is behind: 12 noon − 2 hours = 10 am.

Question 5

Which is the largest circle of latitude on Earth?

  1. Aकर्क रेखा
  2. Bमकर रेखा
  3. Cभूमध्य रेखा
  4. Dआर्कटिक वृत्त

Explanation

The Equator (0° latitude) is the largest latitude circle on Earth. The size of latitude circles keeps shrinking moving towards the poles.

Question 6

How does the distance between longitude lines change as one moves towards the poles?

  1. Aबढ़ती जाती है
  2. Bस्थिर रहती है
  3. Cघटती जाती है और ध्रुव पर शून्य हो जाती है
  4. Dपहले बढ़ती फिर घटती है

Explanation

Longitude lines are semicircles that meet at both poles, so the distance between them keeps shrinking moving from the Equator towards the poles, becoming zero at the poles.

Question 7

At which latitude is the Tropic of Cancer located?

  1. A0°
  2. B23.5° उत्तर
  3. C23.5° दक्षिण
  4. D66.5° उत्तर

Explanation

The Tropic of Cancer lies at 23.5° North latitude and passes through the middle of India (through 8 states, including Gujarat and Rajasthan). The Tropic of Capricorn lies at 23.5° South latitude.

Question 8

The International Date Line runs roughly along which longitude?

  1. A0°
  2. B90°
  3. C180°
  4. D82.5°

Explanation

The International Date Line runs roughly along the 180° longitude, but it is drawn zigzag to keep landmasses and island groups within a single date. Crossing it changes the date by one day.

Question 9

What is the approximate difference in local time between the easternmost and westernmost points of India?

  1. Aलगभग 30 मिनट
  2. Bलगभग 1 घंटा
  3. Cलगभग 2 घंटे
  4. Dलगभग 4 घंटे

Explanation

India's longitudinal extent runs roughly from 68°7'E to 97°25'E (about 30°), which is why there's a difference of about 2 hours (30° × 4 minutes = 120 minutes) between the local time at its eastern and western edges.

Question 10

What is the most effective way to clearly explain the difference between latitude and longitude in class?

  1. Aकेवल परिभाषा बोर्ड पर लिखना
  2. Bग्लोब या गेंद पर वास्तव में रेखाएँ खिंचवाकर दिखाना
  3. Cविषय को केवल किताब से पढ़वाना
  4. Dबिना उदाहरण के सीधे संख्यात्मक प्रश्न हल करवाना

Explanation

Actually drawing latitude (horizontal) and longitude (vertical) lines on a globe or ball helps children clearly see and understand the difference in shape and direction between the two, which reading a definition alone cannot achieve.

Frequently asked questions

How many REET questions come from Latitude and Longitude?+

REET 2024 carried 2 questions from this topic, both numerical questions based on time calculation. It's a topic that appears regularly in the Geography section.

What is the time difference for 1° of longitude?+

Earth rotates 360° in 24 hours, so the time difference for 1° of longitude is 4 minutes (24×60÷360 = 4 minutes).

What is India's standard meridian?+

India's standard meridian is 82°30' East longitude, which passes near Mirzapur in Uttar Pradesh. Indian Standard Time (IST) is based on this line (GMT+5:30).

What is the distance between two longitude lines at the Equator?+

At the Equator, the distance between two consecutive longitude lines (1° apart) is about 111 km. This distance shrinks moving towards the poles, becoming zero at the poles.

What is the main difference between latitude and longitude lines?+

Latitude lines are parallel circles with a roughly constant distance between them, while longitude lines are semicircles that meet at the poles, and their distance shrinks moving from the Equator towards the poles.

Why does the whole of India keep a single standard time (IST) instead of separate time zones?+

Even though India's longitudinal spread of about 30° creates a natural time difference of about 2 hours, the whole country has adopted a single standard time (based on the 82.5°E longitude) for uniformity and simplicity in rail traffic, communication and administration, rather than setting up separate time zones.

At which latitude does the Tropic of Capricorn lie?+

The Tropic of Capricorn lies at 23.5° South latitude. It does not pass through India, but runs through parts of Australia, South Africa and South America in the Southern Hemisphere.

Read next

District Administration

Previous topic

Movements of the Earth

Next topic

REET Syllabus

The full syllabus in one place

REET 2024 Solved Paper

Solved questions from every subject

Official Sources

  1. NCERT Class 6 Social Science — Chapter 1: Locating Places on the Earth

Change Log

  • 17 September 2026 — English page published — mirrors the fact-checked Hindi page, independently bilingual-accuracy checked