Geographic Grid: Latitudes and Longitudes - Q&A

I. Choose the correct option:

1. The imaginary lines running east to west on a globe are called ________ while those running north to south are called ________

(a) Latitude, Longitude
(b) Longitude, Latitude
(c) Equator, Prime Meridian
(d) All of the above.

Answer: (a) Latitude, Longitude
Explanation: Lines of latitude are drawn horizontally parallel to the Equator (east to west), whereas lines of longitude are drawn vertically connecting the North and South poles (north to south).

2. Name the criss-crossing lines on a globe that form a framework.

(a) Geographic Framework
(b) Geographic Grid
(c) Geographic Matrix
(d) Geographic Lines

Answer: (b) Geographic Grid
Explanation: The network formed by the intersection of horizontal latitudes and vertical longitudes is called the Geographic Grid, which is used to precisely locate places on Earth.

3. Which of the following is true about the lines of Latitude?

(a) They are imaginary lines
(b) They are parallel to the Equator
(c) They reduce in length as we go towards the poles.
(d) All of the above.

Answer: (d) All of the above.
Explanation: Latitudes are imaginary parallel lines that wrap around the Earth. Because the Earth is a sphere, these circular lines get progressively smaller as you move from the Equator towards the poles.

4. In each hemisphere for which latitude the length of the circle is half the length of the Equator?

(a) 30°
(b) 45°
(c) 60°
(d) 90°

Answer: (c) 60°
Explanation: At the 60° latitude (both North and South), the length of the circular line is exactly half the circumference of the Equator due to the curvature of the Earth.

5. The total number of the parallels of Latitude are

(a) 180
(b) 182
(c) 183
(d) 181

Answer: (d) 181
Explanation: There are 90 lines of latitude in the Northern Hemisphere, 90 lines in the Southern Hemisphere, plus 1 line for the Equator (0°). So, 90 + 90 + 1 = 181.

6. The poles are located at what angular distance from the Equator.

(a) 90°
(b) 45°
(c) 60°
(d) 0°

Answer: (a) 90°
Explanation: The angular distance from the Equator to either pole forms a right angle at the center of the Earth, which is exactly 90°.

7. Which of the following heat zones are correct?

(a) Frigid Zone: 66½°N to 66½°S
(b) Temperate Zone: 90°N to 90°S
(c) Torrid Zone: 23½°N to 23½°S
(d) All of the above.

Answer: (c) Torrid Zone: 23½°N to 23½°S
Explanation: The Torrid (hottest) zone lies strictly between the Tropic of Cancer (23½°N) and the Tropic of Capricorn (23½°S).

8. Which of the following is true about lines of longitude?

(a) They run parallel to the Prime Meridian.
(b) They are full circles
(c) They are 360 lines at 1° interval.
(d) All of the above.

Answer: (c) They are 360 lines at 1° interval.
Explanation: There are exactly 360 lines of longitude (meridians) drawn at 1° intervals. They are not parallel (they converge at the poles) and individually they are semi-circles, not full circles.

9. See the above figure and answer the following questions.
1. What would be the value of angle AOB?
(a) 40°
(b) 20°
(c) 10°
(d) 140°

Answer: (a) 40°
Explanation: Longitude is defined as the angular distance from the Prime Meridian. Since point B lies on the 40° Meridian, the angle formed at the center (AOB) is 40°.

2. The circle through EQ is a
(a) Great circle
(b) Small circle
(c) Semi-circle
(d) Both (a) and (b)

Answer: (a) Great circle
Explanation: EQ represents the Equator, which is the only line of latitude that passes through the exact center of the Earth, dividing it into two equal hemispheres. Therefore, it is a Great Circle.

3. Identify the relationship between length of the Prime Meridian and that of 40° Meridian.
(a) >
(b) <
(c) =
(d) ≤

Answer: (c) =
Explanation: Unlike latitudes, all lines of longitude (meridians) run from the North Pole to the South Pole and are of exactly equal length.

10. Assertion (A): 1° angular distance of the parallels of latitudes is roughly equal to 111 km.
Reason (R): The poles are each located at 90° angular distance north or south of the Equator.

(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R does not explain A.
(c) A is true but R is false.
(d) A is false but R is true.

Answer: (b) Both A and R are true but R does not explain A.
Explanation: Both statements are factually correct. However, 1° is 111 km because the total circumference of the Earth (40,075 km) is divided by 360°, not simply because the poles are at 90°.

11. The distance between two lines of longitude is maximum at which latitude?

(a) Tropic of Cancer
(b) North Pole
(c) Equator
(d) Arctic circle

Answer: (c) Equator
Explanation: Since longitudes converge (meet) at the poles, they are furthest apart at the widest part of the Earth, which is the Equator (approx 111 km apart).

12. Assertion (A): All places on a particular meridian will have noon at the same time.
Reason (R): The sun crosses a meridian at noon.

(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R does not explain A.
(c) A is true but R is false.
(d) A is false but R is true.

Answer: (a) Both A and R are true and R is the correct explanation of A.
Explanation: The word 'meridian' actually means noon. Whenever the sun is directly overhead at a specific longitude, it is noon for every single location along that entire vertical line.

13. The Earth has been divided into how many Time Zones?

(a) 48
(b) 20
(c) 12
(d) 24

Answer: (d) 24
Explanation: The Earth takes 24 hours to complete one rotation (360°). Therefore, it is divided into 24 distinct time zones, each representing one hour of rotation (15° wide).

14. What is Standard Time?

(a) Uniform time based on a central meridian.
(b) Time at 0° longitude
(c) Time at 82°30'E
(d) Time at 7½° longitudes at 12 noon.

Answer: (a) Uniform time based on a central meridian.
Explanation: To avoid the confusion of having multiple local times in one region, a country selects a central meridian and applies its specific time uniformly across the entire region.

15. Which of the following is true about the International Date Line?

(a) It goes zig-zag at two points.
(b) The date changes as one moves across it.
(c) It is opposite the Prime Meridian.
(d) All of the above.

Answer: (d) All of the above.
Explanation: The IDL is the 180° meridian (opposite the 0° Prime Meridian). Crossing it causes a date change, and it intentionally zig-zags around specific islands (like Fiji and the Bering Strait) so that a single country doesn't experience two different dates simultaneously.

16. Assertion (A): For each 1° longitude towards the East, 4 minutes are to be added and each 1° longitude towards the West, 4 minutes are to be subtracted.
Reason (R): The earth rotates on its axis from East to West.

(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R does not explain A.
(c) A is true but R is false.
(d) A is false but R is true.

Answer: (c) A is true but R is false.
Explanation: The math rule (EGA-WLS) is true: East-Gain-Add, West-Lose-Subtract. However, the reason is false because the Earth actually rotates from West to East, which is why the sun rises in the East first.

17. I travelled from Tokyo, Japan to Alaska, USA. I was very sad to lose a day. How did this happen?

(a) Crossed the IDL
(b) Crossed the Pacific Ocean
(c) Crossed over to another country
(d) Crossed the Prime Meridian.

Answer: (a) Crossed the IDL
Explanation: Traveling from Japan (East) to Alaska (West) across the Pacific means you are crossing the International Date Line going eastward. According to the rule, when you cross the IDL going East, you "lose" a day (e.g., Sunday becomes Monday).

18. It was midnight at the Fiji Islands. What would be the time in London?

(a) 8:00 am
(b) 12:00 noon
(c) 8:00 pm
(d) None of the above.

Answer: (b) 12:00 noon
Explanation: Fiji sits near the 180° line, meaning it is approximately 12 hours ahead of London (which is at the 0° Prime Meridian). If it is exactly midnight (12:00 AM) in Fiji, it is 12 hours behind in London, making it 12:00 noon of the previous day.

19. A great circle is a circle drawn on the surface of a sphere with radius

(a) equal to the radius of the sphere.
(b) equal to half the radius of the sphere.
(c) larger than the radius of the sphere.
(d) less than the radius of the sphere.

Answer: (a) equal to the radius of the sphere.
Explanation: By mathematical definition, a Great Circle cuts a sphere exactly in half, meaning its center is the center of the Earth, and its radius is identical to the radius of the Earth itself.

20. Which of the following are great circles?

(a) Lines of Longitudes
(b) Lines of Latitudes
(c) Equator
(d) Both (a) and (c)

Answer: (c) Equator
Explanation: The Equator is the only line of latitude that is a great circle. (Note: While pairs of opposite longitudes form a great circle, individual lines of longitude are just semi-circles).

21. Assertion (A): There is a time difference of a full day on crossing the IDL.
Reason (R): It is diametrically opposite the Greenwich Meridian.

(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R does not explain A.
(c) A is true but R is false.
(d) A is false but R is true.

Answer: (a) Both A and R are true and R is the correct explanation of A.
Explanation: Because the IDL (180°) is directly opposite the Prime Meridian (0°), the time difference works out to 12 hours from the East and 12 hours from the West. Combined, this creates an exact 24-hour (full day) difference when you step across the line.

22. Assertion (A): Great circles are used to find the shortest distance between any two points on the earth's surface.
Reason (R): Great circle routes take into account weather or political restrictions.

(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R does not explain A.
(c) A is true but R is false.
(d) A is false but R is true.

Answer: (c) A is true but R is false.
Explanation: While navigators use Great Circles to find the absolute shortest mathematical path between two points, these theoretical routes do not take real-world variables like bad weather or restricted political airspaces into account.

II. Short Answer Questions

1. What is a geographic grid? How does the geographic grid serve the same purpose as co-ordinates on a graph?

Answer:
A geographic grid is a framework of criss-crossing imaginary lines (latitudes and longitudes) drawn on a globe or map. Just like x and y axes on a graph paper pinpoint an exact mathematical point, the horizontal lines (latitudes acting as the x-axis) and vertical lines (longitudes acting as the y-axis) intersect to help us precisely locate any place on the Earth's vast surface.

2. What are lines of latitude and longitude? Who devised the lines of latitude and longitude?

Answer:
Lines of Latitude are imaginary lines running horizontally east to west, parallel to the Equator.
Lines of Longitude are imaginary vertical lines running north to south, passing through the poles.
They were originally devised by Eratosthenes, an ancient Greek philosopher who also calculated the circumference of the earth.

3. Mention two characteristics of lines of latitude.

Answer:
1. They are parallel to the Equator and to each other, so they never intersect.
2. They are not of equal length; they form full circles that become progressively smaller as you move from the Equator towards the poles, eventually becoming just dots at 90° N and 90° S.

4. Name the two hemispheres of the earth made by the Equator. Name the thermal zones of the earth.

Answer:
Hemispheres: The Equator divides the earth into the Northern Hemisphere and the Southern Hemisphere.
Thermal (Heat) Zones: Based on latitude, the earth is divided into the Torrid Zone (hottest), the Temperate Zones (North and South, having moderate climate), and the Frigid Zones (North and South, freezing polar regions).

5. List any two uses of the lines of latitude. Express 1° angular distance in kilometres.

Answer:
Uses:
1. To accurately find the absolute location of a place north or south of the Equator.
2. To divide the earth into distinct heat or climatic zones (Torrid, Temperate, Frigid).
Distance: 1° of angular distance of latitude is roughly equal to 111 kilometres.

6. With the help of a diagram, show the important lines of latitude.

Answer:
(Draw a circle representing the Earth and mark the following horizontal lines):
1. Equator: 0°
2. Tropic of Cancer: 23½° N
3. Tropic of Capricorn: 23½° S
4. Arctic Circle: 66½° N
5. Antarctic Circle: 66½° S
6. North Pole & South Pole: 90° N and 90° S respectively.

7. Which line is known as the Prime Meridian? State its importance.

Answer:
The line of longitude whose angular distance is exactly 0° is known as the Prime Meridian. It passes through Greenwich near London.
Importance: It serves as the global reference point for calculating standard time (Greenwich Mean Time or GMT) and, along with the 180° meridian, divides the Earth into the Eastern and Western Hemispheres.

8. How can the general climate of an area be described with the help of the lines of latitude?

Answer:
Latitudes help determine how direct the sun's rays are on a specific region, dividing the earth into heat belts:
- Places located near the Equator (between 23½°N and 23½°S) fall in the Torrid Zone and have a very hot climate.
- Places located in the mid-latitudes (23½° to 66½°) fall in the Temperate Zone and have a moderate climate.
- Places located near the poles (above 66½°) fall in the Frigid Zone and receive slanting rays, making the climate freezing cold.

9. Which line of longitude is used to fix the World Standard Time? State its value in degrees. State the longitudinal value in degrees of Indian Standard Meridian.

Answer:
World Standard Time: Fixed by the Prime Meridian (Greenwich Meridian), which has a value of 0°.
Indian Standard Meridian: The central meridian used to fix time for India is 82°30' E (or 82.5° E).

10. List any two characteristics of the Great Circles.

Answer:
1. A great circle intersects the exact center of the Earth, dividing the sphere into two completely equal halves.
2. Intersecting great circles will always bisect (cut exactly in half) each other.

11. List any two uses of the Great Circles.

Answer:
1. Navigation: Pilots and ship captains use them to find the absolute shortest physical route between two distant points on the globe.
2. Meteorology: Meteorologists use great circles to determine climate and weather patterns across broad regions.

12. What are the Great Circle Routes? State their importance.

Answer:
A Great Circle Route is the shortest mathematical path between any two locations on the Earth's curved surface, traveling along the arc of a great circle.
Importance: They are critically important for long-distance aviation and maritime navigation, as flying or sailing along these specific routes saves a tremendous amount of fuel and time compared to following standard compass lines.

III. Structured Questions

1. (a) State the five lines of latitude.

Answer:
1. Equator (0°)
2. Tropic of Cancer (23½°N)
3. Tropic of Capricorn (23½°S)
4. Arctic Circle (66½°N)
5. Antarctic Circle (66½°S)

1. (b) What is the significance of these lines of latitude?

Answer:
These specific major latitudes are significant because they act as boundaries for the Earth's thermal (heat) zones. They mark the limits of the sun's apparent movement and denote regions where the Earth receives direct overhead sunlight (Torrid zone), slanted moderate sunlight (Temperate zones), or extreme slanting sunlight (Frigid zones), directly dictating global climate.

1. (c) Give a geographical reason for each of the following:
(i) Lines of latitude are called parallels of latitude.
(ii) Lines of latitude are not of equal length.
(iii) Lines of latitude carve out the heat zones of the earth.

Answer:
(i) They are drawn completely parallel to the Equator and to one another, meaning the distance between any two specific latitudes remains exactly the same (~111 km) all around the globe, and they never intersect.
(ii) Because the Earth is spherical, it is widest at the middle. Therefore, as the circular lines of latitude are drawn further north or south toward the poles, the sphere becomes narrower, forcing the circles to become progressively smaller in length.
(iii) The angle at which the sun's rays strike the Earth changes depending on the latitude. Latitudes near the Equator receive intense, direct rays, while higher latitudes receive weak, slanted rays. Thus, latitudes perfectly carve out distinct temperature belts or "heat zones."

1. (d) Draw a well labelled diagram showing the different heat zones of the world.

Answer:
(Instructions for drawing based on the text):
Draw a circle. Mark 0° as Equator. Mark 23.5°N (Tropic of Cancer) and 23.5°S (Tropic of Capricorn); label the area between them as Torrid Zone. Mark 66.5°N (Arctic Circle) and 66.5°S (Antarctic Circle); label the areas between 23.5° and 66.5° as Temperate Zones. Label the top (up to 90°N) and bottom (up to 90°S) as Frigid Zones.

2. (a) Describe the lines of longitude.

Answer:
Lines of longitude are imaginary semi-circles drawn vertically on the globe. They run from the North Pole to the South Pole, intersecting at both ends. Unlike latitudes, all longitudes are of equal length. They measure the angular distance of a place East or West of the 0° Prime Meridian, with a total of 360 lines spaced at 1° intervals.

2. (b) State the use of the lines of longitude in relation to distance and time.

Answer:
Distance: When intersected with lines of latitude, longitudes complete the geographic grid, allowing us to accurately locate the exact position of any place on Earth.
Time: Longitudes are the absolute basis for calculating time. Because the Earth rotates 1° of longitude every 4 minutes, the local time of any place is directly tied to its specific longitude.

2. (c) Give a geographical reason for each of the following:
(i) Lines of longitude are called meridians of longitude.
(ii) Lines of longitude are of same length.
(iii) Diametrically opposite lines of longitude and the Equator are called Great Circles.

Answer:
(i) The word 'meridian' comes from the Latin word 'meridianum', meaning noon. They are called meridians because all places located on the same vertical line of longitude experience solar noon at the exact same time.
(ii) Because every single line of longitude starts exactly at the North Pole and ends exactly at the South Pole, tracing the exact same curve of the Earth's surface, they all have the exact same length.
(iii) A Great Circle must pass through the exact center of the Earth, dividing it into two equal halves. The Equator does this horizontally. Any two diametrically opposite longitudes (like 0° and 180°) connect to form a full circle that cuts vertically through the Earth's center, also making them Great Circles.

2. (d) Draw a well labelled diagram to show that places on the same longitude have the same time.

Answer:
(Instructions for drawing):
Draw a globe. Draw the central Prime Meridian (0°). Draw another vertical line to its right and label it "40° Meridian". Pick three points along this 40° line: top (M), middle (O), and bottom (K). Write a caption: "Places K, O, and M all lie on the 40° Meridian. When the sun is overhead, it is exactly 12 Noon at K, O, and M simultaneously."

3. (a) State the meaning of the International Date Line.

Answer:
The International Date Line (IDL) is an imaginary line approximately following the 180° longitude in the Pacific Ocean. It is the designated boundary where the calendar date officially changes. Because it sits exactly opposite the Prime Meridian, crossing this line results in either a gain or loss of a full 24-hour day.

3. (b) State with an example how time lost or gained is computed with reference to the International Date Line.

Answer:
Rule: Crossing the IDL from West to East = Lose a day. Crossing from East to West = Gain a day.
Example: Imagine a ship sailing across the Pacific. If it is 8:00 AM on Monday on the western side of the line (towards Asia), the moment the ship crosses the IDL traveling eastward toward America, the calendar date shifts back by 24 hours. So, the moment they cross the line, the time becomes 8:00 AM on Sunday. They have "lost" a calendar day.

3. (c) Give a geographical reason for each of the following:
(i) The International Date Line deviates and goes zig-zag near some islands in the Pacific Ocean.
(ii) The Greenwich time is called the Greenwich Mean Time.
(iii) Great Circles are the shortest routes between two places.

Answer:
(i) If the IDL were a perfectly straight vertical line, it would slice directly through countries like Fiji and Tonga. This would mean two different dates would exist inside the same country on the same day, causing massive administrative confusion. Therefore, it deliberately bends (zig-zags) around these islands to keep them on a unified date.
(ii) Greenwich sits at the 0° longitude. As standard time zones for the entire world were developed, the time at this specific meridian was mathematically selected as the baseline, or "mean" starting point, from which all other global time zones are calculated (either added to or subtracted from).
(iii) On a flat map, a straight line looks like the shortest distance. But on a 3D spherical Earth, the surface curves. Following the arc of a Great Circle cuts directly across this curve (rather than wrapping wide around the sphere), providing the shortest possible physical distance between two points.

3. (d) State with one practical example how is time of a place found with the help of longitudes.

Answer:
Step-by-Step Example: We know that for every 1° of longitude, there is a 4-minute time difference. Suppose we want to find the time in New Delhi (77°E) when it is exactly 12:00 Noon in Mumbai (73°E).
1. Find the longitudinal difference: 77° - 73° = 4°.
2. Convert degrees to minutes: 4° × 4 minutes/degree = 16 minutes.
3. Apply the EGA rule (East-Gain-Add): Since New Delhi is to the East of Mumbai, we add the time.
4. Result: 12:00 Noon + 16 minutes = 12:16 PM in New Delhi.

IV. Time-related Questions:

1. An important programme was to be broadcast from Mumbai at 7:30 p.m. This was heard by some Indian sailors near Ivory Coast in West Africa at 20°W longitude. What was the local time there?

Answer:
Step 1: Mumbai uses Indian Standard Time (IST), which is based on 82.5°E.
Time at IST = 7:30 p.m. (19:30 hours).
Since IST is 5½ hours ahead of Greenwich (GMT 0°), the time at GMT is 19:30 - 5:30 = 2:00 p.m. (14:00 hours).
Step 2: The sailors are at 20°W.
Time difference from GMT = 20° × 4 minutes = 80 minutes (1 hour 20 minutes).
Step 3: Since they are West of Greenwich, we subtract (WLS rule):
14:00 hours - 1 hour 20 minutes = 12:40 hours.
Local Time: 12:40 p.m.

2. What is the longitude of a place where the local time is 1:15 p.m., when it is 4 a.m. at Chicago (88°W)?

Answer:
Step 1: Find the time difference.
Time at Chicago = 4:00 a.m.
Time at Place = 1:15 p.m. (13:15 hours).
Difference = 9 hours 15 minutes = (9 × 60) + 15 = 555 minutes.
Step 2: Calculate the longitudinal difference.
Longitude degrees = 555 ÷ 4 = 138.75° (138° 45').
Step 3: Determine direction.
Since the local time (1:15 p.m.) is ahead of Chicago (4 a.m.), the place is to the East of Chicago.
Calculation: Start at 88°W and move East by 138.75°.
88°W to 0° covers 88°.
Remaining degrees East of prime meridian = 138.75° - 88° = 50.75°E.
Longitude: 50°45' E

3. Calculate the time at Durban (longitude 30°E) when the time is 7:00 am. at New York (75°W).

Answer:
Step 1: Find total longitudinal difference.
New York is 75°W and Durban is 30°E.
Total difference = 75° + 30° = 105°.
Step 2: Calculate time difference.
105° × 4 minutes = 420 minutes = 7 hours.
Step 3: Determine direction and final time.
Durban is to the East of New York, so we ADD the time (EGA rule).
7:00 a.m. + 7 hours = 14:00 hours.
Time at Durban: 2:00 p.m.

4. Calculate the longitude of a place where the local time is 6:00 a.m., when the time is 9:00 p.m. at New Delhi on longitude 77°E.

Answer:
Step 1: Find the time difference.
New Delhi time = 9:00 p.m. (21:00 hours).
Local time = 6:00 a.m.
Difference = 15 hours = 900 minutes.
Step 2: Calculate longitudinal difference.
Longitude degrees = 900 ÷ 4 = 225°.
Step 3: Determine direction.
Since the time (6:00 a.m.) is behind New Delhi (9:00 p.m.), the place is to the West of New Delhi.
Calculation: Start at 77°E and move West by 225°.
77°E to 0° covers 77°.
Remaining degrees West = 225° - 77° = 148°W.
Longitude: 148° W

5. Calculate the local time at Singapore (104°E) when it is 6:00 p.m. at Greenwich.

Answer:
Step 1: Find longitudinal difference.
Greenwich is 0°. Singapore is 104°E. Difference = 104°.
Step 2: Calculate time difference.
104° × 4 minutes = 416 minutes = 6 hours 56 minutes.
Step 3: Determine final time.
Singapore is to the East of Greenwich, so we ADD the time.
6:00 p.m. (18:00) + 6 hours 56 minutes = 24:56 hours.
Local Time: 12:56 a.m. (next day).

6. Calculate the location of a place where the local time is noon when it is 7:30p.m. at Greenwich.

Answer:
Step 1: Find time difference.
Greenwich time = 7:30 p.m. (19:30 hours).
Local time = 12:00 Noon.
Difference = 7 hours 30 minutes = 450 minutes.
Step 2: Calculate longitudinal difference.
450 minutes ÷ 4 minutes/degree = 112.5° (112°30').
Step 3: Determine direction.
Since Noon is behind 7:30 p.m., the place must be to the West of Greenwich.
Location: 112°30' W

7. What is the time and day at Mumbai (73°E) when it is Sunday 10:30 p.m. at Shillong (92°E)? Give a reason to support your answer.

Answer:
Step 1: Find longitudinal difference.
Shillong (92°E) - Mumbai (73°E) = 19° difference.
Step 2: Calculate time difference.
19° × 4 minutes = 76 minutes = 1 hour 16 minutes.
Step 3: Determine final time.
Mumbai is geographically to the West of Shillong. Therefore, Mumbai's local time is behind Shillong's (Subtract).
10:30 p.m. - 1 hour 16 minutes = 9:14 p.m.
Time and Day: 9:14 p.m. on Sunday.
Reason: Because the Earth rotates from West to East, eastern places experience sunrise and sunset earlier. Since Mumbai is 19 degrees West of Shillong, its local time lags behind by 76 minutes.

V. Thinking Skills

1. Find the latitude of your city and state how has this influenced the climate of your city.

Answer:
(As an example for a student in Pune, India):
The latitude of Pune is approximately 18.5°N. Because it lies between the Equator (0°) and the Tropic of Cancer (23.5°N), Pune is situated directly within the Torrid Zone. This specific latitudinal location ensures that the city receives strong, direct sunlight for most of the year, resulting in a generally hot, tropical climate rather than a freezing or temperate one.

2. Your home town is located at a place which receives the slanting rays of the sun. How is the temperature of your home town different from your boarding school, located at a place that receives the vertical rays of the Sun?

Answer:
If my hometown receives slanting rays of the sun, it means it is located in a higher latitude (likely the Temperate Zone or Frigid Zone). Slanting rays spread their heat over a much larger surface area and travel through more atmosphere, losing intensity. Therefore, my hometown will have a much cooler, moderate, or even cold temperature. My boarding school, receiving vertical (direct) rays, is located in the Torrid Zone near the Equator, meaning the heat is intensely concentrated in a smaller area, resulting in a much hotter climate.

3. Find out the name of the country which has the maximum number of time zones in the world. What is reason behind a country having many time zones and others like India have just one time zone.

Answer:
Country: France has the maximum number of time zones (12 zones) if you include all its overseas territories globally. However, for continuous landmass, Russia has 11 time zones.
Reason: A country requires multiple time zones if it has a massive East-West geographical spread (like Russia or the USA) because the sun rises at vastly different times across its massive breadth. In contrast, a country like India has a relatively smaller East-West extent (about 30° of longitude), so relying on a single central Standard Time (82.5°E) is manageable and avoids administrative confusion.

4. When you were waiting to welcome New Year in India on December 31, some countries of the world like Australia, New Zealand and Japan have already welcomed New Year. What is the reason for this?

Answer:
The Earth rotates on its axis from West to East. Because of this rotation, the sun rises first in the easternmost parts of the globe. Countries like Japan, Australia, and New Zealand are located far to the East of India (and very close to the International Date Line). Therefore, they rotate into the new day (January 1st) several hours before India does.

VI. Project/Activity

Look at the map of the Time Zones (Fig. 2.7) and answer the following questions:

1. What is the Longitudinal degree of IST?

Answer:
The Indian Standard Time (IST) is based on the central meridian of 82°30' E (82.5° East).

2. If it is 2 a.m. IST what will be the Time at Tokyo, London, San Francisco?

Answer:
If it is 2:00 a.m. IST, the GMT is 8:30 p.m. (previous day) since India is 5.5 hours ahead of GMT.
- Tokyo: Japan is GMT + 9 hours. So, 8:30 p.m. + 9 hours = 5:30 a.m. (They are 3.5 hours ahead of India).
- London: London is roughly on GMT (0°). The time will be 8:30 p.m. (of the previous day).
- San Francisco: SF is in the Pacific Time Zone (approx GMT - 8 hours). 8:30 p.m. - 8 hours = 12:30 p.m. (afternoon of the previous day).

3. Name the place which is diametrically opposite of India.

Answer:
To find the exact opposite, we reverse latitude and subtract longitude from 180°. India is roughly 20°N and 80°E. The diametrically opposite location is roughly 20°S and 100°W. This specific coordinate is located in the South Pacific Ocean, far off the western coast of South America.

4. Is the Indian Standard Time ahead of San Francisco Time? Give reasons for your answer.

Answer:
Yes, Indian Standard Time is significantly ahead of San Francisco Time.
Reason: India is located in the Eastern Hemisphere (82.5°E), while San Francisco is located in the Western Hemisphere (approx 122°W). Because the Earth rotates from West to East, places in the East encounter the morning sun long before places in the West. Therefore, India's clocks are approximately 13.5 hours ahead of San Francisco's.