WBBSE Class 6 Geography WBBSE Chapter 2 Is the Earth Round Topic A The Spherical Earth Analytical Type Questions
Question 1. Give Proof of the spherical shape of the earth.
Answer:
Some facts that give proof of the spherical shape of the Earth are as follows:
1. Photographs received from outer space: Photographs sent by artificial satellites that orbit the Earth show that the Earth is indeed spherical in shape.
2. Observation of the Earth’s shadow: When the Earth’s shadow falls on the Moon during a lunar eclipse, it is observed to be spherical. It implies that the object casting the shadow is also spherical.
3. Observation of a ship leaving shore: When a ship sails away from shore, first its hull, then its deck, and finally the entire ship disappears from view. This happens because the Earth is spherical.
WBBSE Class 6 Spherical Earth Notes
4. Observation of the horizon: As we climb up a mountain or we ascend in an aeroplane, the circumference of the horizon seems to expand and the shape seems to be circular.
5. Bedford Level Experiment: In 1870 AD, renowned naturalist and surveyor A.R Wallace put in 3 equal stakes in a straight line at equal intervals in the Bedford Canal of the United Kingdom.
Through a telescope, he observed that the second stake seemed to be higher than the first and the third stake.
This proved that the Earth is round. If the Earth were a flat disc, the tops of the stakes would be in a straight line.
Class 6 Geography WBBSE
Question 2. Who was the first to have the idea of a round Earth?
Answer:
People who believed that the Earth is round shaped are-
Aristotle: Aristotle, a Greek philosopher, observed the falling shadow of the Earth on the Moon during a lunar eclipse and he concluded that the Earth must be having a round shape.
Eratosthenes: Greek philosopher cum geographer Eratosthenes, standing on the seashore in 200 BCE, saw the disappearance of a sailing ship and concluded that the Earth is round.
3. Aryabhatta: Indian scientist Aryabhatta (in 476 CE) supported the idea of the round Earth.
Magellan: Magellan, a Portuguese explorer, sailed continuously westwards, circumnavigating the Earth, and finally returned to the same port. This voyage made him sure that the Earth has a circular shape.
Question 3. Give a few practical proofs of the Earth’s spherical shape.
Answer:
A few practical proofs of the Earth’s spherical shape are—
Instance 1: When one observes a ship leaving shore, first it’s the hull, then it’s a deck, and finally the entire ship seems to disappear from view.
Instance 2: when one looks down from a mountaintop, it seems as if the Earth is a spherical object and the sky covers it like a dome. It seems as if the Earth and the sky are meeting at a distant, arc-shaped line.
Instance 3: During a lunar eclipse, the shadow of the Earth falls on the Moon. This shadow is round and it proves that the Earth is spherical in shape.
Common Questions About Earth’s Roundness
Question 4. How did Magellan’s expedition of 1519 prove that the Earth is round?
Answer:
Magellan’s expedition of 1519 prove that the Earth is round:
The famous Portuguese explorer, Magellan, set out in 1519 to circumnavigate the globe with a fleet of five ships.
They always went westwards and after three years, they ended up at that port where they had set sail from. This circumnavigation clearly proves that the Earth is not a flat disc.
If we consider the Earth as a flat disk, then just by travelling to the west continuously, the ships would not have returned where they had started from. This proved beyond doubt that the Earth is round.
Question 5. What is Lunar Eclipse? How does the Phenomenon of lunar Eclipse Prove that the Earth is round?
Answer:
Lunar Eclipse:
All heavenly bodies revolve in space in their own unique orbits. The Earth revolves around the Sun and the Moon revolves around the Earth in their own orbits.
If at any point during their revolutions, the Earth comes between the Sun and the Moon in a straight line.
Class 6 Geography Question Answer WBBSE
The Sun’s light is unable to reach the Moon because the Earth’s shadow falls on the Moon. This is called a lunar eclipse.
During a lunar eclipse, the Earth’s shadow that falls on the Moon is seen to be circular in shape. This shows that the shape of the Earth is round.
Greek philosopher Aristotle was the first person to observe that the Earth is round in shape by noticing the circular shadow of the Earth during the lunar eclipse.
Only a circular or spherical object can have a circular shadow. Even when we see through a telescope, all other planets are seen to be spheres. So, it is natural to deduce that the Earth is also spherical in shape.
Practice Questions on Earth’s Spherical Nature
Question 6. Write a short note on the horizon.
Answer:
Horizon:
The line where the surface of the Earth and the sky meet is the horizon. The imaginary line that traces the horizon is called the line of the horizon.
When we stand on a flat stretch of land, our line of sight ends at a distant point where the sky and the surface of the Earth meet.
This is the horizon. This seems to be a straight line. When we stand on a mountain peak, the line of the horizon appears to be an arc.
When our line of sight is obstructed by trees or buildings, the skyline is called the visible horizon.
Class 6 Geography Question Answer WBBSE
Question 7. What does the Earth’s shape seem like from space?
Answer:
Earth’s shape seem like from space:
As seen from outer space, the Earth looks like a bright, blue sphere suspended in space.
The photographs sent by astronauts from space and from the Moon and also those taken by artificial satellites show that the Earth is spherical.
But, calculations have shown that the Earth is actually an oblate spheroid—not quite a sphere. Geographers think that there is no object existing on earth which is similar in shape to that of the Earth.
So the Earth should be described to have a unique shape like that of itself.
Question 8. Why the Earth apparently seems to be flat?
Answer:
Earth apparently seems to be flat:
The Earth apparently seems to be flat to those who live on earth, because—
1. The radius of the Earth is about 6,400 km. As a result, the curvature of the circumference of the Earth is huge, which is normally not visible to the human eye.
2. The visible limit of surroundings to the naked human eye from any point on the Earth’s surface is very low. As a result, the farthest a person can see from any location appears merely flat.
Important Definitions Related to Earth’s Shape
Question 9. Why the Sun Rises at different times at Different places on earth?
Answer:
Sun Rises at different times at Different places on earth:
The Earth apparently seems to be flat to those who live on earth, because—
The radius of the Earth is about 6,400 km. As a result, the curvature of the circumference of the Earth is huge, which is normally not visible to the human eye.
The visible limit of surroundings to the naked human eye from any point on the Earth’s surface is very low. As a result, the farthest a person can see from any location appears merely flat.
WBBSE Chapter 2 Is The Earth Round Topic A The Spherical Earth Short Answer Type Questions
Question 1. From where can we get photographs of the Earth?
Answer:
We can get photographs of the Earth from man-made satellites orbiting in space.
Question 2. What do you understand by the horizon?
Answer:
Horizon:
When we stand on a vast, open ground or in a wide open space and look around us, the Earth and the sky seem to meet at an arc-shaped line. This line is called the horizon. The horizon always remains circular.
Examples of Evidence for Earth’s Roundness
Question 3. How did people use to determine direction before the compass was invented?
Answer:
In ancient times before the compass was invented, people used the Pole Star to determine north, Hadley’s Octant to determine south, the Morning Star to determine east in the morning and Evening Star to determine west in the evening.
WBBSE Chapter 2 Is The Earth Round Topic A The Spherical Earth Very Short Answer Type Questions
Question 1. The Earth is round”—who was the first person to say this?
Answer: Pythagoras.
Question 2. The Earth is round” – who was the first Indian scientist to think this?
Answer: Aryabhatta.
Question 3. Who was the first person to deduce that the Earth is round by observing the shadow of a lunar eclipse?
Answer: Greek philosopher Aristotle.
Question 4. What is the average radius of the Earth?
Answer: 6,400km.
WBBSE Class 6 Geography Question Answer
Question 5. During a lunar eclipse, whose shadow falls on the Moon?
Answer: The Earth’s shadow.
Question 6. What shape is the line of the horizon?
Answer: Circular.
Question 7. Which heavenly body helped ancient people to determine the southern direction?
Answer: Hadley’s Octant.
Question 8. Which instrument was used by the navigators to determine the direction of navigation in ancient times?
Answer: Compass.
WBBSE Chapter 2 Is The Earth Round Topic A The Spherical Earth Fill in the blanks
Question 1. In 1519, Portuguese explorer___________set out to travel around the world with a fleet of five ships.
Answer: Magellan
Question 2. The greater the radius of an arc,___________ the curvature is going to be.
Answer: Lesser
Question 3. The horizon always remains ___________
Answer: Circular or arc Shaped
Question 4. If you imagine the Earth to be a flat stretch of land, the sky is like a huge___________ upturned on it.
Answer: Saucer
Question 5. Images showing the Earth’s spherical shape have been taken from artificial ___________.
Answer: Satellites
Question 6. Greek philosophers concluded that the Earth is round by observing the circular shadow of the Earth on the ___________ Moon during the lunar eclipse.
Answer: Aristotle
Question 7. The ancient Indian scientist ___________ endorsed the idea of a round Earth.
Answer: Arya Bhatta
Question 8. The Earth’s spherical shape was first scientifically proven by mathematician ___________.
Answer: Aristotle
WBBSE Chapter 2 Is The Earth Round Topic A The Spherical Earth Write True Or False
Question 1. Almost 500 years before the birth of Christ, Greek mathematician and philosopher Eratosthenes said that the Earth is round.
Answer: False
Question 2. The mean radius of the Earth is 6,400 km.
Answer: True
Question 3. In photographs taken from space, the Earth appears like a flat disc.
Answer: False
Question 4. During a lunar eclipse, the Earth casts a round shadow on the Moon.
Answer: False
Question 5. Greek philosopher Aristotle stated that the Earth’s shape is earth-shaped or geoid.
Answer: False
Question 6. The Earth rotates on its own axis.
Answer: True
Question 7. When a ship sails away from shore, first its mast, then its deck, and finally the entire ship disappears from view.
Answer: False
Question 8. The ocean looks like a sphere when viewed from the deck of a ship.
Answer: True
WBBSE Chapter 2 Is The Earth Round Topic A The Spherical Earth Match The Columns
Questions 1.
Answer: 1-D,2-A,3-E,4-B,5-C