NCERT Solutions For Class 6 Geography Chapter 3 Motions of the Earth

NCERT Solutions For Class 6 Geography Chapter 3 Motions of the Earth

Geography Chapter 3 Motions of the Earth Exercises

Question 1. Answer the following questions briefly.

(1) What is the angle of inclination of the Earth’s axis with its orbital plane?

Answer:

The angle of inclination of the Earth’s axis with its orbital plane is 66 ½.

(2) Define rotation and revolution.

Answer:

The movement of the Earth on its axis is called rotation. The movement of the Earth around the Sun in a fixed path or orbit is called revolution.

(3) What is a leap year?

Answer:

  • The Earth takes 365 days (one year) and 6 hours to revolve around the Sun. The time of 6 hours is ignored for the sake of convenience and only a year is considered.
  • The time of 6 hours saved every year is added to make one day (24 hours) over the span of four years. This extra day is added to the month of February, thus in every fourth year, February is 29 days instead of 28 days. The year with 366 days is called a leap year.

(4) Differentiate between the Summer and Winter Solstice.

Answer:

The differences between the summer and winter solstice are as follows

NCERT Solutions For Class 6 Geography Social Science Chapter 3 Motions of the Earth Difference Between Summer Solstice And Winter Solstice

(5) What is an equinox?

Answer:

An equinox occurs twice a year, on the 21st of March and the 23rd of September when the whole Earth experiences equal days and equal nights. It is because neither of the poles is tilted towards the Sun and the equator receives direct Sun rays.

(6) Why does the Southern Hemisphere experience winter and summer solstice at different times than that of the Northern Hemisphere?

Answer:

  • The Southern Hemisphere experiences winter and summer solstices at times different from those of the Northern Hemisphere because of the Earth’s inclination and revolution.
  • The Tropic of Capricorn receives direct Sun rays due to the tilting of the South Pole towards the Sun on 22nd December. The vertically falling Sun rays at the Tropic of Capricorn 23 yh° S provide heat to a larger portion of it. Therefore, it is summer in the Southern Hemisphere and winter in the Northern Hemisphere.
  • On 21st June, the Northern Hemisphere is tilted towards the Sun. These areas receive more heat because Sun rays fall directly on the Tropic of Cancer and it is summer there while winter in the Southern Hemisphere.

(7) Why do the poles experience about six months of day and six months of night?

Answer:

  • The poles experience about six months of day and six months of night. It is because the North Pole remains inclined towards the Sun for six months due to which places beyond the Arctic Circle experience continuous daylight for about six months while the South Pole remains away from the Sun for six months and experiences night for the same period.
  • The same condition reverses for the next six months when the South Pole inclines towards the Sun and the South Pole experiences day for six months while the North Pole experiences night.

Question 2. Tick the correct answers.

(1) The movement of the Earth around the Sun is known as

  1. rotation
  2. revolution
  3. inclination

Answer: 2. revolution

(2) Direct rays of the Sun fall on the equator on

  1. 21st March
  2. 21st June
  3. 22nd December

Answer: 1. 21st March

(3) Christmas is celebrated in summer in

  1. Japan
  2. India
  3. Australia

Answer: 3. Australia

(4) The cycle of the seasons is caused to

  1. rotation
  2. revolution
  3. gravitation

Answer: 2. revolution

Question 3. Fill in the blanks.

1. A leap year has …….. number of days.

Answer: 366

2. The daily motion of the Earth is ……..

Answer: Rotation

3. The Earth travels around the Sun in ……… orbit

Answer: elliptical

4. The Sun’s rays fall vertically on the Tropic of …… on 21st June.

Answer: Cancer

5. Days are shorter during …….. season.

Answer: winter

Geography Chapter 3 Motions of the Earth Multiple Choice Questions (MCQs)

Question 1. Which imaginary line makes an angle of approximately 66.5 degrees with the Earth’s orbital plane?

  1. Equator
  2. Tropic of Cancer
  3. Arctic Circle
  4. Earth’s axis

Answer: 4. Earth’s axis

Question 2. What divides the day from night on the Earth?

  1. Equator
  2. Circle of Illumination
  3. Meridian line
  4. Tropic of Cancer

Answer: 2. Circle of Illumination

Question 3. How long does the Earth take to complete one rotation on its axis?

  1. 12 hours
  2. 24 hours
  3. 36 hours
  4. 48 hours

Answer: 2. 24 hours

Question 4. The exact time taken for one revolution of the Earth around the Sun is

  1. 365 days 16 hours
  2. 365 days 9 hours
  3. 366 days 6 hours
  4. 365 days 6 hours

Answer: 4. 365 days 6 hours

Question 5. What would have happened if the Earth did not rotate on its axis?

  1. Continuous warmth in all regions
  2. Continuous darkness in all regions
  3. Extreme temperatures in all regions
  4. Life would not have been possible

Answer: 4. Life would not have been possible

Question 6. Who was the ancient Indian astronomer who stated that the Earth is round and rotates on its own axis?

  1. Copernicus
  2. Galileo
  3. Aryabhatta
  4. Kepler

Answer: 3. Galileo

Question 7. Rina is a 23-year-old geography enthusiast from a farming background. She finds that crops in some regions do not receive proper sunlight and rainwater. Then she finds some changes in seasons on Earth.

Which factor plays a significant role in determining the change of seasons on Earth?

  1. The Earth’s axial tilt and its revolution around the Sun.
  2. The Earth’s magnetic field variations.
  3. The speed of the Earth’s rotation on its axis.
  4. The Earth’s distance from the moon.

Answer: 1. The Earth’s axial tilt and its revolution around the Sun.

Question 8. Changes in seasons happen because of

  1. rotation
  2. revolution of Earth
  3. rotation of Moon
  4. None of these

Answer: 2. revolution of Earth

Question 9. How does the Earth’s orbit affect the duration of daylight in different regions?

  1. It has no effect.
  2. It causes longer days and nights simultaneously.
  3. It results in longer days in some regions and shorter days in others.
  4. It causes equal days and nights globally.

Answer: 3. It results in longer days in some regions and shorter days in others.

Question 10. Which position of the Earth leads to the Northern Hemisphere experiencing the longest day on 21st June?

  1. Summer Solstice
  2. Winter Solstice
  3. Equinox
  4. Tropic of Cancer

Answer: 1. Summer Solstice

Question 11. What causes longer days in the Northern Hemisphere during the summer solstice?

  1. Tilt towards the Sun
  2. Tilt away from the Sun
  3. Direct rays of the Sun at the equator
  4. Direct rays of the Sun at the poles

Answer: 1. Tilt towards the Sun

Question 12. An equinox happens each year for how many times?

  1. Thrice
  2. Four Times
  3. Twice
  4. Once

Answer: 3. Twice

Question 13. During Winter Solstice, the pole is close to the Sun.

  1. South
  2. North
  3. Both poles
  4. None of these

Answer: 1. South

Question 14. When do the equinoxes occur on the Earth?

  1. 21st June and 22nd December
  2. 21st March and 23rd September
  3. 20th March and 24th September ’
  4. 22nd March and 20th September

Answer: 2. 21st March and 23rd September

Question 15. What among the following causes the Earth to experience equal days and nights during an equinox?

  1. Tilted poles
  2. Elliptical orbit
  3. Direct rays of the Sun at the poles
  4. Neither pole tilted towards the Sun

Answer: 4. Neither pole tilted towards the Sun

Question 16. What event occurs when the Northern Hemisphere experiences autumn while the Southern Hemisphere experiences spring?

  1. Summer Solstice
  2. Winter Solstice
  3. Spring Equinox
  4. Autumn Equinox

Answer: 4. Autumn Equinox

Question 17. Which of the following statements is/are correct?

  1. Revolution causes day and night.
  2. The period of rotation is called Earth’s day.
  3. Rotation is the movement of the Earth on its axis.

Codes

  1. Only 1
  2. Both 2 and 3
  3. Both 1 and 2
  4. 1, 2 and 3

Answer: 2. Both 2 and 3

Question 18. Which of the following statements is/are incorrect?

  1. The Earth’s axis is tilted about to the orbital plane.
  2. The Earth has only one type of motion.
  3. Winter Solstice occurs on 21st June.

Codes

  1. 1, 2 and 3
  2. 1 and 2
  3. 2 and 3
  4. Only 1

Answer: 3. 2 and 3

Question 19. Javed, an astronomy enthusiast, has been studying the motions of celestial bodies. He observed that Earth has two primary types of motions rotation and revolution. Further, he noted the impact of these motions on the Earth’s seasons and the division of days and nights.

Which of the following statements regarding the Earth’s motions and their consequences is most likely accurate based on the information provided?

  1.  The tilt of the Earth’s axis significantly influences the duration of daylight in different hemispheres, causing seasonal variations.
  2. The Earth’s elliptical orbit leads to irregularities in the lengths of months and creates variations in leap years.
  3. Equinoxes occur due to the Earth’s stationary position relative to the Sun during its revolution.
  4. The circle of illumination is caused by the Earth’s rotation around its axis, resulting in the division of the Earth into day and night

Choose the correct option.

  1. 1 and 3
  2. 1, 2, 3
  3. 2, 3 and 4
  4. All of these

Answer: 4. All of these

Question 20. Arrange the following events according to their chronological order.

  1. Winter Solstice
  2. Summer Solstice
  3. Equinox (Autumn in the North)

Choose the correct option.

  1. 1, 2, 3
  2. 2, 3 and 1
  3. 3, 1, 1
  4. All of these

Answer: 2. 2, 3 and 1

Geography Chapter 3 Motions of the Earth Match The Following

Question.

NCERT Solutions For Class 6 Geography Social Science Chapter 3 Motions of the Earth Match The Following List 1 And List 2

  • A B C D
  1. 1 2 3 4
  2. 3 1 4 2
  3. 4 3 2 1
  4. 4 1 3 2

Answer: 3. 4 3 2 1

Geography Chapter 3 Motions of the Earth Assertion and Reason

1. Assertion (A) The occurrence of seasons on Earth is primarily due to the planet’s axial tilt and its revolution around the Sun.

Reason (R) During the Earth’s revolution around the Sun, the tilt of its axis causes varying exposure to sunlight in different hemispheres, resulting in seasonal changes.

Codes

  1. Both A and R are true and R is the correct explanation of A
  2. Both A and R are true, but R is not the correct explanation of A
  3. A is true, but R is false
  4. A is false, but R is true

Answer: 1. Both A and R are true and R is the correct explanation of A

2. Assertion (A) The summer solstice in the Northern Hemisphere coincides with the longest day of the year.

Reason (R) During the summer solstice, the Northern Hemisphere is tilted towards the Sun, resulting in more direct sunlight and longer daylight hours.

Codes

  1. Both A and R are true and R is the correct explanation of A
  2. Both A and R are true, but R is not the correct explanation of A
  3. A is true, but R is false
  4. A is false, but R is true

Answer: 1. Both A and R are true and R is the correct explanation of A

Geography Chapter 3 Motions of the Earth Fill in the Blanks

Question 1. The Sun’s rays fall vertically on the 21st of June.

Answer: Tropic of Cancer

Question 2. The daily motion of the Earth is

Answer: Rotation

Question 3. The Arctic Circle experiences daylight continuously for…

Answer: 6 months

Question 4. On …….. September is the autumn season in the Northern Hemisphere.

Answer: 23rd

Question 5. Seasons change due to the change in the …….. of the Earth.

Answer: direction of hemispheres

Geography Chapter 3 Motions of the Earth True or False

Question 1. The circle of illumination is responsible for dividing the Earth into summer and winter seasons.

Answer: False

Question 2. The Earth’s axis is inclined at an angle of 66.5 degrees with its orbital plane.

Answer: False

Question 3. Equinox occurs when the Earth’s axis is tilted neither towards nor away from the Sun.

Answer: True

Question 4. The Earth takes 366 days to complete one revolution around the Sun during a leap year.

Answer: True

Geography Chapter 3 Motions of the Earth Picture Based Question

Question 1. Look at the picture given below and answer the following questions

NCERT Solutions For Class 6 Geography Social Science Chapter 3 Motions of the Earth Winter Solstice

When does the winter solstice happen?

  1. 22nd March
  2. 21st June
  3. 22nd December
  4. 21st September

Answer: 3. 22nd December

Geography Chapter 3 Motions of the Earth Case Based Question

1. Read the passage given below and answer the following questions.

  1. The axis of the Earth which is an imaginary line, makes an angle of 66 1/2° with its orbital plane. The plane formed by the orbit is known as the orbital plane.
  2. The Earth receives light from the Sun. Due to the spherical shape of the Earth, only half of it gets light from the Sun at a time. The portion facing the Sun experiences day while the other half away from the Sun experiences night.
  3. The circle that divides the day from night on the globe is called the circle of illumination. The Earth takes about 24 hours to complete one rotation around its axis. The period of rotation is known as the Earthday. This is the daily motion of the Earth.

Question 1. What causes the daily motion of the Earth?

  1. Earth’s revolution around the Sun
  2. Earth’s rotation on its axis
  3. Earth’s magnetic field
  4. Earth’s orbital inclination

Answer: 2. Earth’s rotation on its axis

Question 2. What is the period of rotation of the Earth known as?

  1. Solar day
  2. Lunar day
  3. Sidereal day
  4. Earthday

Answer: 4. Earthday

Question 3. What is the term for the ‘imaginary line’ around which the Earth rotates making an angle of 66V20 with its orbital plane?

  1. Axis
  2. Earth day
  3. Circle of illumination
  4. None of these

Answer: 1. Axis

Question 4. Why does only half of the Earth receive light from the Sun at a time?

  1. Due to its rotation
  2. Due to its spherical shape
  3. Due to its axial tilt
  4. Due to its elliptical orbit

Answer: 2. Due to its spherical shape

2. Read the passage given below and answer the following questions.

  • On 22nd December, the Tropic of Capricorn receives direct rays of the Sun as the South Pole tilts towards it. As the Sun’s rays fall vertically at the Tropic of Capricorn (23 ½° S), a larger portion of the Southern Hemisphere gets light.
  • Therefore, it is summer in the Southern Hemisphere with longer days and shorter nights. The reverse happens in the Northern Hemisphere. This position of the Earth is called the winter solstice.

Question 1. What is the primary reason for the Southern Hemisphere experiencing summer on 22nd December?

Answer:

The Tropic of Capricorn receives direct sunlight as the South Pole tilts towards it, resulting in longer days and shorter nights, leading to summer in the Southern Hemisphere on 22nd December.

Question 2. What is the position of the Earth on 22nd December which is referred to as the winter solstice?

Answer:

The position of the Earth on 22nd December which is referred to as the winter solstice is that the Sun’s rays fall directly on the Tropic of Capricorn and the Southern Hemisphere is tilted towards the Sun, receiving direct sun rays.

Question 3. What is the overall impact on daylight between the hemispheres during the winter solstice?

Answer:

The overall impact on daylight during the winter solstice is that the Southern Hemisphere experiences longer days, while the Northern Hemisphere experiences shorter days.

Geography Chapter 3 Motions of the Earth Very Short Answer Type Questions

Question 1. What are the two types of motion of the Earth?

Answer:

The two types of motion of the Earth are rotation, which is the Earth’s movement on its axis, and revolution, which is the Earth’s movement around the Sun in an orbit.

Question 2. What does the orbital plane of the Earth represent?

Answer:

The orbital plane of the Earth represents the plane formed by the Earth’s orbit around the Sun.

Question 3. What is the axis of the Earth?

Answer:

The axis of the Earth is an imaginary line around which the Earth rotates.

Question 4. How often is a leap year observed?

Answer:

A leap year is observed every fourth year.

Question 5. What causes the change in seasons on Earth?

Answer:

The change in seasons on Earth is caused by the Earth’s position around the Sun.

Question 6. Which hemisphere experiences Christmas in summer?

Answer:

The Southern Hemisphere, including Australia and New Zealand, experiences Christmas in summer.

Question 7. Which hemisphere experiences the longest day on the summer solstice?

Answer:

The Northern Hemisphere experiences the longest day on the summer solstice.

Geography Chapter 3 Motions of the Earth Short Answer Type Questions

Question 1. Differentiate between rotation and revolution of the Earth.

Answer:

NCERT Solutions For Class 6 Geography Social Science Chapter 3 Motions of the Earth Difference Between Rotation And Revolution

Question 2. Why does the circle of illumination not coincide with the axis of the Earth?

Answer:

  • The circle of illumination does not coincide with the axis of the Earth due to the axis’ tilt of 23 ½.
  • This inclination causes the circle of illumination to slant, creating a separation between the illuminated and dark portions of the planet.
  • As the Earth completes one rotation in approximately 24 hours, this division persists, accounting for the alternation between day and night.

Question 3. What would have happened if the earth did not rotate?

Answer:

  • If the Earth didn’t rotate, extreme temperature variations would secure, making life impossible. One side facing the Sun would experience constant daylight, resulting in high temperatures.
  • On the other hand, the side away from Sunlight would experience continuous night, leading to extremely low temperatures. This condition would create harsh extremes: scorching heat on the sunlit side and freezing cold on the dark side.

Question 4. When does the Northern Hemisphere have summer and why?

Answer:

  • The Northern Hemisphere experiences summer on the 21st of June due to its tilt towards the Sun, receiving direct Sunlight on the Tropic of Cancer. This tilt results in increased heat accumulation, mainly in the Northern regions.
  • The larger exposure to sunlight in the Northern Hemisphere during this time causes it to be summer in that part of the equator, marking the onset of the Northern Hemisphere’s summer season.

Question 5. How equinoxes and solstice are viewed?

Answer:

  • Equinoxes and solstices are considered important events signifying the transition between seasons on Earth. These celestial events mark the four primary seasons – summer, winter, autumn, and spring.
  • Equinoxes mark the instances of equal day and night, occurring twice a year, while solstices represent the longest and shortest days, observed during Summer and Winter respectively.
  • These occurrences mark the changing climatic conditions and signify the Earth’s axial tilt and orbital position relative to the Sun

Question 6. Why does the whole Earth not get a day at the same time?

Answer:

  • The entire Earth doesn’t experience daylight at the same time due to the slanting angle of the Sun’s rays caused by the Earth’s tilted position and its movement. Being spherical, only half the Earth receives sunlight at any given moment.
  • The region facing the sun encounters daylight, while the other half remains in darkness, experiencing night due to Earth’s rotation and its spherical shape. This creates a division between day and night.

Question 7. Explain the occurrence and significance of the equinox.

Answer:

  • The equinox occurs twice a year, on 21st March and 23rd September when the Sun’s direct rays fall directly on the Earth’s equator. During this time, neither of the poles is tilted toward the Sun, resulting in an equal duration of day and night across the entire planet.
  • This event marks the instances when the length of daylight and darkness is nearly the same worldwide, symbolizing the equilibrium between day and night.

Question 8. What are the important dates that receive direct Sun rays on different parts of the Earth?

Answer:

The important dates that receive direct Sun rays on different parts of the Earth are as follows

  • On the 21st of March and 23rd of September, the equator receives direct Sun rays during the equinox.
  • On the 21st of June, the Northern Hemisphere experiences direct sunlight during the summer solstice.
  • On 22nd December, the Southern Hemisphere receives direct sun rays during the winter solstice.

Geography Chapter 3 Motions of the Earth Long Answer Type Questions

Question 1. Define the following terms related to the types of motion of the Earth.

  1. Orbital plane
  2. Earthday
  3. Circle of illumination
  4. Elliptical orbit

Answer:

  1.  Orbital Plane The plane formed by the orbit is known as the orbital plane. The axis of the Earth (an imaginary line) makes an angle of 66 ½° with its orbital plane.
  2.  Earthday The Earth takes about 24 hours to complete one rotation around its axis. The period of rotation is known as the Earthday.
  3. Circle of Illumination The circle that divides day from night on the Earth is called the circle of illumination.
  4. Elliptical Orbit When an object moves around another object in an oval-shaped path, it is known to be revolving in an elliptical orbit.

Question 2. How are seasons changed on the Earth?

Answer:

  • Seasonal changes on Earth occur due to two primary factors: the inclination of the Earth’s axis and its position relative to the Sun.
  • The axial tilt, fixed in a particular direction, causes varying exposure to sunlight throughout the year.
  • For example, around 21st June, the Northern Hemisphere is tilted towards the Sun, receiving direct sunlight at the Tropic of Cancer, marking summer in that region.
  • On the other hand, on 22nd December, the Southern Hemisphere experiences summer as the South Pole tilts towards the Sun, directing direct rays at the Tropic of Capricorn.
  • Equinoxes, like 23rd September and 21st March, mark transitions when neither pole is tilted, leading to the onset of autumn in the Northern Hemisphere and spring in the Southern Hemisphere, respectively.
  • These changes in axial tilt and orbital position result in the annual cycle of seasons across the Earth.

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