Globe

Class 6 | Social Science — Geography | Unit 2

Class 6 Unit 2 Geography

Unit 2 Globe

Learning Objectives

• To understand the four cardinal directions.
• To learn about the shape of the Earth.
• To understand about the model of the Earth - the globe.
• To understand the significance of lines of latitudes and longitudes.
• To know how standard time is calculated around the world

Surya and Poovendhan are very good friends who study in the sixth standard and live in a beautiful village called Thirunandriyur. Surya lives in South Street, while Poovendhan lives in North Street. Every day they go to school together. One day.

Surya: Why are you coming so late, Poovendha?

Poovendhan: Please bear with me, Surya! Come, let's go.

Surya: What took you so long?

Poovendhan: You live on South Street. But, I have to come from North Street, which is so far away from here. That's why I'm late.

Surya: Yes, that's true. But wherever we live, don't you remember that we all live on planet Earth?

Poovendhan: Yes! Yes! I do remember, Even our Ponni Miss taught us about the Solar System.

Surya: But, I have a doubt ….

Poovendhan: Tell me, what is it?

Surya: We can see our house, the things around us, the people, animals and birds with our eyes. But, why can't we see our Earth as a whole?

Poovendhan: Haven't you seen it?

Surya: No, I haven't. Have you ever seen it?

Poovendhan: Yes, in our school only.

Surya: Did you say, in our school?

Poovendhan: Yes, on our Ponni Miss' table. Big and spherical!

Surya: Oh! Yes! Like a ball on a stand?

Poovendhan: Exactly! That is our Earth

Surya: But........ But, our teacher said that our Earth is in the Milky Way Galaxy. But you say that our Earth is on our teacher's table. I am so confused. Come, let's go and ask Ponni Miss.

The bell rang as they reached school. They attended the morning assembly and went to the classroom. During the social science period, Surya asks Ponni Miss to clear his doubts.

Surya: Good morning, Miss.

Teacher: Good morning.

Surya: Madam, you told us on the other day that our Earth is in the Milky Way galaxy.

Teacher: Yes, it is true. This is the model of the Earth.

Surya: A model of the earth, Madam? Please explain!

Teacher: Sure, Surya.

The teacher asks all the students to sit down and starts explaining.

Directions

The directions on the ground are always shown with respect to the North. If we know the North, then it is easy to find the other directions, namely South, East and West. These are the four cardinal directions. We know that the Sun rises in the East and sets in the West. If we stand facing the sun in the morning, then we face the east. The west is towards our back. The left hand points towards the north and the right hand points towards the south. We should always keep this in mind.

Globe

We live on the planet Earth, which is found third from the Sun. Since the Earth is huge and we live in a very small area, we are not able to see the Earth as a whole. But, when we travel to space, we can see the Earth as a whole. So, in order to see the shape of the Earth as a whole and to know its unique features, a three dimensional model of the Earth was created with a specific scale.

Do You Know?

The surface area of the Earth is 510.1 million square kilometres. The Earth, which is spherical, is flat at the poles and bulges at the Equator. The Earth cannot be compared with any other geometrical shape as it has a very unique shape. Hence, its shape is called a geoid (earth shaped). The Earth moves around the Sun. It also rotates from the West to East on its axis at an inclination of 23½°. The globe is also inclined at an angle of 23½°. The axis is an imaginary line. It is not actually found on the Earth.

Do You Know?

The first globe was created by the Greeks in the year 150 AD (Common Era). The Indian astronomer Aryabhata was mentioned in his book. 'Aryabhatta Sidhantha'. 'The stars in the sky seem to move towards the West because of the Earth's rotation on its axis'.

Lines on the Globe

There are imaginary lines which are drawn on the globe horizontally and vertically to find a location and calculate distance and time. These imaginary lines are called lines of latitudes and longitudes.

Do You Know?

Ptolemy, a Greco – Roman mathematician, astronomer and geographer, was the first person to draw the lines of latitude and longitude on a map. In his book, 'Geographia' a detailed description about the Earth's surface, its size and circumference and many locations based on the lines of latitude and longitude are given.

Latitudes

The imaginary lines which are drawn horizontally in the East - West direction on the Earth are called the lines or parallels of latitudes. The 0° line of latitude which divides the Earth into two halves is known as the Equator. From the Equator, parallel lines are drawn towards the North and South poles at equal intervals. The latitudinal extent between the 1° line of latitude on Earth is 111 kilometers. Since the Earth is geoid shaped, the length of the lines of latitude decreases from the Equator towards the South and North Poles. The 90-degree North and South Poles are not found as lines, but as points. The lines of latitude that are drawn horizontally between the Equator and the North Pole are called 'Northern Latitudes' and those which are found between the Equator and the South Pole are called 'Southern Latitudes'. The lines of latitude consist of 89 parallels in the Northern Hemisphere and 89 parallels in the Southern Hemisphere, one at the Equator and the two poles are found as points. In total, there are 181 parallels found on earth.

Do You Know?

The Equator is the longest of all lines of latitude. Hence, it is also known as 'The Great Circle'.

Activity

Draw a circle on a paper. Draw a horizontal line across the middle of a circle. Keeping this line as 0°, draw lines on both sides with an equal interval of 15° with the help of a protractor. The lines you have drawn are lines of latitudes.

Northern Hemisphere

The area of the Earth found between the Equator (0°) and the North Pole (90° North) is called the Northern Hemisphere.

Southern Hemisphere

The area of the Earth from the equator (0°) to the South Pole (90° North) is called the Southern Hemisphere. The location of any country or place is based on this division of the hemispheres.

Higher Order Thinking: Based on the latitudinal extent, in which hemisphere is India located?

Important lines of latitude

The earth rotates on its axis at an inclination of 23½°. It also revolves around the sun while rotating. Based on the angle at which the sun's rays fall on the earth, certain lines of latitude gain significance.

Do You Know?

0° North and South – 23½° North and South lines of latitudes are called – Low latitudes
23½° North and South – 66½° North and South lines of latitudes are called – Middle Latitudes
66½° North and South – 90° North and South lines of latitudes are called – High Latitudes
(Source : A Dictionary of Geography – Susan Mayhew, Oxford University Press, Fifth edition 2015)

The Sun's rays do not fall equally on all parts of the earth. They fall vertically over the Equator and slanting towards the poles. Thus, all the places on earth do not have the same amount of temperature. Based on the amount of heat received from the Sun, the lines of latitude help in dividing the earth into different climatic zones.

Torrid Zone

The region from the Equator towards the Tropic of Cancer (23½° North) and the Tropic of Capricorn (23½° South) is called the Torrid Zone. The Sun's rays fall vertically over this region and the average temperature is very high. Hence this region is known as the Torrid Zone.

Temperate Zone

From the Tropic of Cancer (23° North) to the Arctic Circle (66½° North) and from the Tropic of Capricorn (23½° South) to the Antarctic Circle (66½° South), the Sun's rays fall slantingly. Moderate temperature prevails in this region. Hence, this region is called the Temperate Zone.

Frigid Zone

From the Arctic Circle (66½° North) to the North Pole (90° North) and from the Antarctic Circle (66½° South) to the South Pole (90° South), the Sun's rays fall further inclined, throughout the year. The temperature is very low. Hence, this region is known as Frigid Zone.

Do You Know?

Some lines of latitude are also called by the following names in Tamil.
Latitude ahalangu (ஆகலாங்கு)
Longitude nettangu (நெட்டாங்கு)
Equator nilanduvarai (நிலநடுவரை)
Tropic of Cancer kadagavarai (கடகவரை)
Tropic of Capricorn magaravarai (மகரவரை)
(Source: Ariviyal Kalanjiyam, The Tamil University)

Longitudes

The imaginary lines drawn vertically connecting the North Pole and the South Pole are called lines or meridians of longitude. These lines of longitude are seen as semi circles. The 0° line of longitude is called the Prime Meridian. There are 180 lines of longitude towards the East and West from the Prime Meridian. So, there are totally 360 lines of longitude. These lines converge at the poles. The 180° West and 180° East line of longitude are the same line. The lines of longitude that are found between the Prime Meridian and the 180° East line of longitude are called 'Eastern Longitudes' and the lines of longitude that are found between the Prime Meridian (0°) and the 180° West line of longitude are called 'Western Longitudes'. Two opposite meridians form a great circle.

Do You Know?

The lines of longitude are found as semi circles covering 111 kilometers at the Equator, 79 kilometers at 45° latitude and no space between the lines at the poles.

Activity

Take a ball and a thin iron wire. Pierce the ball with the wire from one end to the other end through the middle. Remove the wire. Draw circles around the points. Name the northernmost point as North Pole and the southernmost point as South Pole. The angle of a circle is 360°. Mark points on the circle at an interval of 15° using a protractor. Then draw lines joining these points on the top and bottom of the ball. The lines that you have drawn are lines of longitudes

Eastern Hemisphere

The part of the Earth between the 0° line of longitude and the 180° East line of longitude is known as the Eastern Hemisphere.

Western Hemisphere

The part of the Earth from 0° line of longitude to 180° West line of longitude is called as Western Hemisphere.

Activity

Based on the longitudinal extent, in which hemisphere is our country located? Look at the globe and answer.

Significant Lines of Longitude

Greenwich Meridian

The Royal Astronomical Observatory is located at Greenwich near London in England. According to the International Meridian Conference held in 1884 in Washington DC in the United States of America all nations agreed on choosing the Greenwich Meridian as the international standard meridian (0°). This line of longitude is called the Prime Meridian and it is also known as the Greenwich Meridian because it passes through Greenwich.

International Date Line

The 180° line of longitude has been fixed as the International Date Line, drawn on the Pacific Ocean between Alaska and Russia through the Bering Strait. If a person crosses this line from the West to East, he loses a day. On the other hand, when he crosses from the East to West, he gains a day. Based on this, the date is fixed for different countries or regions of the world.

Do You Know?

The International Date Line is not straight. If the line is drawn straight, two places in the same country would have different dates. So, the International Date Line is found zigzag in certain places to avoid confusion.

Earth Grid

The imaginary lines of latitude and longitude form a grid-like pattern on the surface of the earth, known as the 'Earth grid' or 'Geographic grid'. To locate a place exactly on earth, the latitudinal and longitudinal extensions are required.

Longitude and Time

As many as 360 lines of longitude are drawn to connect the North and South Poles around the Earth 180° on the Eastern Hemisphere and 180° on the Western Hemisphere. Time is calculated on the basis of the lines of longitude.

Do You Know?

Fact
The Earth takes one day to rotate on its axis.
1 day = 24 hours
1 hour = 60 minutes
24 hours = 24 × 60 = 1440 minutes
The angle of the earth = 360°
360° = 360 Longitudes
360° = 1440 minutes
So 1° = 1440 ÷ 360 = 4 minutes
360 = 4 minutes
In 4 minutes = 1° rotation
In 60 minutes = 60 ÷ 4 = 15° rotation
So, in an hour (60 minutes) the earth rotates 15°

Local Time

When the sun is overhead on a particular line of longitude, it is 12 noon at all the places located on that line of longitude. This is called local time. The Sun is overhead on a line of longitude only once in a day. So the local time differs for every line of longitude. When the Sun is overhead the Greenwich Meridian at 12 noon, it is the local time of that place. The world time is calculated by this standard line of longitude. It is known as the Greenwich Mean Time (GMT). For example, if the time is 12 noon at Greenwich Meridian, it is 12:04 P.M. at 1° East line of longitude and 11:56 A.M. at 1° West line of longitude. So, as one moves towards the east from any meridian the time increases. And if one moves towards the west from any meridian, time decreases.

Do You Know?

1. The word meridian is derived from the Latin word 'Meridianus'. It means mid day. (Medius – Middle, dies – day). So, meridian means the position of the Sun found overhead at a place at noon.
2. A.M 'ante Meridiem' (ante before) Before Noon.
3. P.M. means 'post Meridiem' (Post after or later) After noon

Standard Time

Local time is calculated when the sun is overhead at noon. Many lines of longitude may pass through a country. Countries may or may not observe a common time. The standard time of a country or a part of it is calculated keeping a particular meridian as a standard one. The meridians are selected in multiples of 15° or 7½°. It is done in such a way that the variation of standard time from Greenwich is expressed either as 1 hour or half an hour.

Indian Standard Time

The longitudinal extent of India is from 68° 7' East to 97° 25' East. As many as twenty nine lines of longitude pass through India. Having 29 standard time is not logical. Hence 82½° E line of longitude is observed as the Prime Meridian to calculate the Indian Standard Time (IST).

Do You Know?

The 82½° E line of longitude passes through Mirzapur near Allahabad in Uttar Pradesh. This is located at an equal distance from Ghuar Mota in Gujarat and Kibithu in Arunachal Pradesh.

Time Zones

The world has 24 time zones. Some countries have a great longitudinal extent. So they have more than one standard time. Example: Russia has 7 time zones.

Activity

1. What is the difference in time between the Greenwich Mean Time and Indian Standard Time?

2. If it is 5 A.M. in New York City, United States of America, what would be the time at New Delhi, the capital of India?

3. If it is 12 Midnight at London, what would be the time in India?

4. The standard time of Sydney city in Australia is found to be at a difference of hours from that of the Greenwich Mean Time.

5. Mr. Senthamizh travels by flight from Chennai to London. He boarded the aeroplane at 9a.m After 12 hours of travel, at what time (Greenwich Mean Time) would he have reached London?

We saw about the lines of latitude and longitude drawn on the globe. Besides these, physical landforms, seas, oceans, countries etc., are also found on the globe

Wrap Up

1. The imaginary lines drawn horizontally from the East to West on the globe and maps are called lines of latitude or parallels.
2. The imaginary lines drawn vertically from the North to South on the globe and maps are known as lines of longitude or meridians.
3. The 0° line of latitude is called the Equator.
4. The 0° line of longitude is called the Greenwich Meridian or the Prime Meridian.
5. The part of the Earth from the Equator (0°) to North Pole (90°) is called the Northern Hemisphere and from the Equator (0°) to South Pole (90°) is called the Southern Hemisphere.
6. The part of the Earth from the Greenwich Meridian (0°) to 180° East line of longitude is called the Eastern Hemisphere and from Equator (0°) to 180° West line of longitude is called the Western Hemisphere.
7. Lines of latitude are circles which are drawn at a distance of about 111 kilometers. The poles are shown as points.
8. Lines of longitude are drawn as semi circles. The distance between the lines of longitude at the Equator is 111 kilometres. It is found at a distance of 79 kilometres at 45° latitude and they converge at the poles.
9. Lines of latitude do not merge, while lines of longitude converge at the poles.
10. Time is calculated on the basis of the lines of longitude. The 180° line of longitude is the International Date Line.

Glossary

Globe A model of the earth Lines of Latitude or Parallels Imaginary lines drawn horizontally on the Earth from the East to West Lines of Longitude or Meridians Imaginary line drawn vertically on the Earth from the North to South Geoid The shape of the Earth Hemisphere Dividing the earth on the basis of 0° lines of latitude and longitude with regard to directions Equator The line of latitude drawn horizontally at the centre of the Earth Tropic of Cancer 23½° North line of latitude Tropic of Capricorn 23½° South line of latitude Arctic Circle 66½° North line of latitude Antarctic Circle 66½° South line of latitude

Exercise

Exercise 1. Choose the correct answer

1. The shape of the Earth is ____

a) Square b) Rectangle c) Geoid d) Circle

2. The North Pole is

a) 90° North Latitude b) 90° South latitude c) 90° West Longitude d) 90° East longitude

3. The area found between 0° and 180° East lines of longitude is called

a) Southern Hemisphere b) Western Hemisphere c) Northern Hemisphere d) Eastern Hemisphere

4. The 23½° North line of latitude is called ____

a) Tropic of Capricorn b) Tropic of Cancer c) Arctic Circle d) Antarctic Circle

5. 180° line of longitude is

a) Equator b) International Date Line c) Prime Meridian d) North Pole

6. The Sun is found overhead the Greenwich Meridian at

a) 12 midnight b) 12 noon c) 1 P.M d) 11 A.M.

7. A day has ____

a) 1240 minutes b) 1340 minutes c) 1440 minutes d) 1140 minutes

8. Which of the following lines of longitude is considered for the Indian Standard Time?

a) 82½° East b) 82½° West c) 81½° East d) 81½° West

9. The total number of lines of latitude are

a) 171 b) 161 c) 181 d) 191

10. The total number of lines of longitude are

a) 370 b) 380 c) 360 d) 390 Exercise 2. Fill in the blanks

1. The line of latitude which is known as the Great Circle is .

2. The imaginary lines drawn horizontally on Earth from the West to East are called .

3. The 90° lines of latitude on the Earth are called .

4. The Prime Meridian is also called .

5. The world is divided into time zones.

Exercise 3. Circle the odd one

1. North Pole, South Pole, Equator, International Date Line.

2. Tropic of Capricorn, Tropic of Cancer, Equator, Prime Meridian.

3. Torrid Zone, Time Zone, Temperate Zone, Frigid Zone.

4. Royal Astronomical observatory, Prime Meridian, Greenwich Meridian, International Date Line.

5. 10° North, 20° South, 30° North, 40° West.

Exercise 4. Match the following

A	B
0° line of latitude
0° line of longitude
180° line of longitude
90° line of latitude

Options: Pole, International Date Line, Greenwich, Equator

Exercise 5. Examine the following statements

1. The Earth is spherical in shape.
2. The shape of the Earth is called a geoid.
3. The Earth is flat.

Look at the options given below and choose the correct answer

a) 1 and 3 are correct b) 2 and 3 are correct c) 1 and 2 are correct d) 1,2 and 3 are correct Exercise 6. Examine the following statements

Statement 1: The lines of latitude on Earth are used to find the location of a place and define the heat zones on Earth.
Statement 2: The lines of longitudes on Earth are used to find the location of a place and to calculate time.

Choose the correct option

a) Statement 1 is correct 2 is wrong b) Statement 1 is wrong 2 correct c) Both the statements are correct d) Both the statements are wrong Exercise 7. Name the following

1. The imaginary lines drawn horizontally on Earth.

2. The imaginary lines drawn vertically on Earth.

3. The three-dimensional model of the Earth.

4. India is located in this hemisphere based on lines of longitude.

5. The network of lines of latitude and longitude.

Exercise 8. Answer briefly

1. What is a Geoid?

2. What is local time?

3. How many times would the sun pass overhead a line of longitude?

4. What are lines of latitude and longitude?

5. Name the four hemispheres of the Earth.

Exercise 9. Give reasons

1. The 0° line of longitude is called the Greenwich Meridian.

2. The regions on Earth between North & South lines of latitude (66½°) and poles (90°) is called Frigid Zone

3. The International Date Line runs zigzag.

Exercise 10. Answer in detail

1. What are the uses of the globe?

2. How are the hemispheres divided on the basis of lines of latitude and longitude? Explain with diagrams.

3. What are the significant lines of latitude? Explain the zones found between them.

4. Explain: Indian Standard Time.

Exercise 11. Activity

There are five positions marked on the grid given below. Look at them carefully and fill the blanks with reference to the lines of latitude and longitude. The first one is done for you.

The latitudinal and longitudinal reference of point A

ANSWER: 40° North 30° West

The latitudinal and longitudinal reference of point B

ANSWER:

The latitudinal and longitudinal reference of point C

ANSWER:

The latitudinal and longitudinal reference of point D

ANSWER:

The latitudinal and longitudinal reference of point E

ANSWER:

Reference

1. Goh Cheng Leong, Certificate Physical and Human Geography (2009), Oxford University Press, New Delhi, India.
2. A Dictionary of Geography – Susan Mayhew, Oxford University Press, Fifth edition -2015.
3. அறிவியல்களஞ்சியம் (தொகுதிகள்), தஞ்சை தமிழ் பல்கலைக்கழகம் வெளியீடு .
4. The earth shape and gravity (1965) Oxford Degman Press.
5. Strahler, Physical Geopraphy Fourth Edition (1965) New York MC Graw – Hill BookCo

ICT CORNER

Globe

Through this activity you will know about the globe model.

Steps:
Step 1 Use the URL or scan the QR code to open the activity page.
Step 2 Click the red "hot spot" area to see the main landmarks of the globe.
Step 3 In the view box Click the "Core" option to view the Earth's inner layers.
Step 4 Drag and rotate the Globe you can rotate the Globe.

Browse in the link
Web: https://solarsystem.nasa.gov/planets/earth/overview/
(or) scan the QR Code

Book-back Exercises — Questions & Answers

Answers generated strictly from the Samacheer Kalvi textbook content. Attempt each question first, then click "Show Answer" to check.

1. Choose the correct answer

1. The shape of the Earth is ____

a) Square b) Rectangle c) Geoid d) Circle

Answer: c) Geoid

Explanation: The Earth cannot be compared with any other geometrical shape as it has a very unique shape. Hence, its shape is called a geoid (earth shaped).

2. The North Pole is

a) 90° North Latitude b) 90° South latitude c) 90° West Longitude d) 90° East longitude

Answer: a) 90° North Latitude

Explanation: The 90-degree North and South Poles are not found as lines, but as points.

3. The area found between 0° and 180° East lines of longitude is called

a) Southern Hemisphere b) Western Hemisphere c) Northern Hemisphere d) Eastern Hemisphere

Answer: d) Eastern Hemisphere

Explanation: The part of the Earth between the 0° line of longitude and the 180° East line of longitude is known as the Eastern Hemisphere.

4. The 23½° North line of latitude is called ____

a) Tropic of Capricorn b) Tropic of Cancer c) Arctic Circle d) Antarctic Circle

Answer: b) Tropic of Cancer

Explanation: The 23½° North line of latitude is called the Tropic of Cancer.

5. 180° line of longitude is

a) Equator b) International Date Line c) Prime Meridian d) North Pole

Answer: b) International Date Line

Explanation: The 180 degree line of longitude has been fixed as the International Date Line.

6. The Sun is found overhead the Greenwich Meridian at

a) 12 midnight b) 12 noon c) 1 p.m. d) 11 a.m.

Answer: b) 12 noon

Explanation: When the Sun is overhead the Greenwich Meridian at 12 noon, it is the local time of that place.

7. A day has ____

a) 1240 minutes b) 1340 minutes c) 1440 minutes d) 1140 minutes

Answer: c) 1440 minutes

Explanation: 1 day = 24 hours, 24 hours = 24 × 60 = 1440 minutes.

8. Which of the following lines of longitude is considered for the Indian Standard Time?

a) 82½° East b) 82½° West c) 81½° East d) 81½° West

Answer: a) 82½° East

Explanation: 82½° E line of longitude is observed as the Prime Meridian to calculate the Indian Standard Time (IST).

9. The total number of lines of latitude are

a) 171 b) 161 c) 181 d) 191

Answer: c) 181

Explanation: The lines of latitude consist of 89 parallels in the Northern Hemisphere and 89 parallels in the Southern Hemisphere, one at the Equator and the two poles are found as points. In total, there are 181 parallels found on earth.

10. The total number of lines of longitude are

a) 370 b) 380 c) 360 d) 390

Answer: c) 360

Explanation: There are 180 lines of longitude towards the East and West from the Prime Meridian. So, there are totally 360 lines of longitude.

2. Fill in the blanks

1. The line of latitude which is known as the Great Circle is ____.

Answer: Equator

2. The imaginary lines drawn horizontally on Earth from the West to East are called ____.

Answer: lines of latitude or parallels

3. The 90° lines of latitude on the Earth are called ____.

Answer: poles

4. The Prime Meridian is also called ____.

Answer: Greenwich Meridian

5. The world is divided into ____ time zones.

Answer: 24

3. Circle the odd one

1. North Pole, South Pole, Equator, International Date Line.

Answer: International Date Line

2. Tropic of Capricorn, Tropic of Cancer, Equator, Prime Meridian.

Answer: Prime Meridian

3. Torrid Zone, Time Zone, Temperate Zone, Frigid Zone.

Answer: Time Zone

4. Royal Astronomical observatory, Prime Meridian, Greenwich Meridian, International Date Line.

Answer: Royal Astronomical observatory

5. 10° North, 20° South, 30° North, 40° West.

Answer: 40° West

4. Match the Following

4. Match the Following

A	B
0° line of latitude	Pole
0° line of longitude	International Date Line
180° line of longitude	Greenwich
90° line of latitude	Equator

Answers: 1-Equator, 2-Greenwich, 3-International Date Line, 4-Pole

5. Examine the following statements

5. Examine the following statements
1. The Earth is spherical in shape.
2. The shape of the Earth is called a geoid.
3. The Earth is flat.
Look at the options given below and choose the correct answer

a) 1 and 3 are correct b) 2 and 3 are correct c) 1 and 2 are correct d) 1, 2 and 3 are correct

Answer: c) 1 and 2 are correct

Explanation: The Earth, which is spherical, is flat at the poles and bulges at the Equator. The shape of the Earth is called a geoid.

6. Examine the following statements

6. Examine the following statements
Statement 1: The lines of latitude on Earth are used to find the location of a place and define the heat zones on Earth.
Statement 2: The lines of longitudes on Earth are used to find the location of a place and to calculate time.
Choose the correct option

a) Statement 1 is correct 2 is wrong b) Statement 1 is wrong 2 correct c) Both the statements are correct d) Both the statements are wrong

Answer: c) Both the statements are correct

Explanation: Lines of latitude help in dividing the earth into different climatic zones and finding locations. Lines of longitude are used to calculate time and find locations.

7. Name the following

1. The imaginary lines drawn horizontally on Earth.

Answer: Lines of latitude

2. The imaginary lines drawn vertically on Earth.

Answer: Lines of longitude

3. The three-dimensional model of the Earth.

Answer: Globe

4. India is located in this hemisphere based on lines of longitude.

Answer: Eastern Hemisphere

5. The network of lines of latitude and longitude.

Answer: Earth Grid

8. Answer briefly

1. What is a Geoid?

Answer: The Earth cannot be compared with any other geometrical shape as it has a very unique shape. Hence, its shape is called a geoid (earth shaped).

2. What is local time?

Answer: When the sun is overhead on a particular line of longitude, it is 12 noon at all the places located on that line of longitude. This is called local time.

3. How many times would the sun pass overhead a line of longitude?

Answer: The Sun is overhead on a line of longitude only once in a day.

4. What are lines of latitude and longitude?

Answer: There are imaginary lines which are drawn on the globe horizontally and vertically to find a location and calculate distance and time. These imaginary lines are called lines of latitudes and longitudes.

5. Name the four hemispheres of the Earth.

Answer: Northern Hemisphere, Southern Hemisphere, Eastern Hemisphere, and Western Hemisphere.

9. Give reasons

1. The 0° line of longitude is called the Greenwich Meridian.

Answer: The Royal Astronomical Observatory is located at Greenwich near London in England. This line of longitude is called the Prime Meridian and it is also known as the Greenwich Meridian because it passes through Greenwich.

2. The regions on Earth between North & South lines of latitude (66½°) and poles (90°) is called Frigid Zone.

Answer: From the Arctic Circle (66½°North) to the North Pole (90°North) and from the Antarctic Circle (66½°South) to the South Pole (90°South), the Sun's rays fall further inclined, throughout the year. The temperature is very low. Hence, this region is known as Frigid Zone.

3. The International Date Line runs zigzag.

Answer: The International Date Line is not straight. If the line is drawn straight, two places in the same country would have different dates. So, the International Date Line is found zigzag in certain places to avoid confusion.

10. Answer in detail

1. What are the uses of the globe?

Answer: Since the Earth is huge and we live in a very small area, we are not able to see the Earth as a whole. In order to see the shape of the Earth as a whole and to know its unique features, a three dimensional model of the Earth was created with a specific scale. This model is called a globe. The globe helps us understand the Earth's shape, features, locations of countries, physical landforms, seas, oceans, and the lines of latitude and longitude drawn on it.

2. How are the hemispheres divided on the basis of lines of latitude and longitude? Explain with diagrams.

Answer: Based on lines of latitude: The area of the Earth found between the Equator (0°) and the North Pole (90°North) is called the Northern Hemisphere. The area of the Earth from the equator (0°) to the South Pole (90°South) is called the Southern Hemisphere. Based on lines of longitude: The part of the Earth between the 0° line of longitude and the 180°East line of longitude is known as the Eastern Hemisphere. The part of the Earth from 0° line of longitude to 180°West line of longitude is called the Western Hemisphere.

3. What are the significant lines of latitude? Explain the zones found between them.

Answer: The significant lines of latitude are: Equator (0°), Tropic of Cancer (23½°North), Tropic of Capricorn (23½°South), Arctic Circle (66½°North), and Antarctic Circle (66½°South). The zones are: Torrid Zone - from the Equator to the Tropic of Cancer and Tropic of Capricorn, where Sun's rays fall vertically and temperature is very high. Temperate Zone - from Tropic of Cancer to Arctic Circle and Tropic of Capricorn to Antarctic Circle, where Sun's rays fall slantingly and moderate temperature prevails. Frigid Zone - from Arctic Circle to North Pole and Antarctic Circle to South Pole, where Sun's rays fall further inclined and temperature is very low.

4. Explain: Indian Standard Time.

Answer: The longitudinal extent of India is from 68°7'East to 97°25'East. As many as twenty nine lines of longitude pass through India. Having 29 standard times is not logical. Hence 82½°E line of longitude is observed as the Prime Meridian to calculate the Indian Standard Time (IST). The 82½°E line of longitude passes through Mirzapur near Allahabad in Uttar Pradesh. This is located at an equal distance from Ghuar Mota in Gujarat and Kibithu in Arunachal Pradesh.

📝 Summary

1. The four cardinal directions are North, South, East and West, with the Sun rising in the East and setting in the West to help us determine our orientation.
2. The Earth is a huge planet that is third from the Sun, and because we live in a very small area, we cannot see the Earth as a whole unless we travel to space.
3. A globe is a three-dimensional model of the Earth created with a specific scale to help us see the shape of the Earth as a whole and understand its unique features.
4. The Earth has a unique shape called a geoid (earth-shaped) because it is spherical but flat at the poles and bulges at the Equator, with a surface area of 510.1 million square kilometres.
5. The Earth rotates from West to East on its axis at an inclination of 23½ degrees while moving around the Sun, and globes are also inclined at the same 23½ degree angle.