NCERT Solutions for Chapter 3 Motions of the Earth Class 6 Geography
Rotation is defined as the movement of the Earth around its axis. A rotation takes 24 hours or a day. Revolving around the Sun is the movement of the Earth in its orbit. An ecliptic or ecliptic plane is Earth's orbital plane around the Sun. The circle of illumination is the imaginary line that separates day from night on Earth. Every fourth year has 29 days in february. It is called leap year, therefore the year has 366 days. The summer solstice occurs when the North Pole is at its maximum tilt toward the Sun. One of the Earth's poles (North Pole) has its maximum tilt away from the Sun during the winter solstice. During the 21st of March and 23rd of September, direct sunlight falls on the equator. The poles are not tilted towards the sun at this position. Consequently, all Earth's days and nights are equal. It is called the equinox.
Chapter Name | Motions of the Earth NCERT Solutions |
Class | CBSE Class 6 |
Textbook Name | Geography |
Related Readings |
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Question 1 A: What is the angle of inclination of the earth's axis with its orbital plane?
Answer
The tilted position of the earth's axis is called the inclination. The earth makes an angle of 66°with the orbital plane.
Question 1 B: Define rotation and revolution.
Answer
Rotation: Rotation can be defined as the movement of the earth on its axis.
Revolution: The movement of the earth around the sun in a fixed path or orbit is known as a Revolution.
Question 1 C: What is a leap year?
Answer
A year with 366 days is called a leap year. It takes 365 days (one year) to revolve around the sun. Six hours saved every year are added to make one day (24 hours) over a span of four years. This surplus day is added to the month of February. Thus every fourth year, February is of 29 days instead of 28 days.
Question 1 D: Differentiate between the Summer and Winter Solstice.
Answer
Summer Solstice: It occurs on 21st June and is also known as the longest day of the year in the Northern Hemisphere. This is due to the position of the earth when there is summer in the Northern Hemisphere and winter in the Southern Hemisphere.
Winter Solstice: Winter Solstice occurs on 22nd December, which is also known as the shortest day of the year. At this time, the earth's North Pole is tilted farthest from the sun. It is summer in the Southern Hemisphere and winter in the Northern Hemisphere.
Question 1 E: What is an equinox?
Answer
Equinox is that time of the year when day time and night time are of equal length. The word Equinox is derived from the Latin; 'equi' means equal and 'nox' means 'night'. It occurs on two such, 21st March and 23rd September.
Question 1 F: Why does the Southern Hemisphere Experience Winter and Summer Solstice in different times than that of the Northern Hemisphere?
Answer
Due to the revolution of the earth on its axis, the Southern hemisphere receives direct sunlight in the month of December and the Northern Hemisphere is away and receives less sunlight. Since a large portion of the Southern Hemisphere faces the sun, it experiences Summer Solstice while the other half away from the sun experiences Winter Solstice.
Question 1 G: Why do the poles experience about six months' day and six months' night?
Answer
Due to the angle of inclination of the earth, both the poles experience day for 6 months and night for 6 months. The pole that is tilted towards the sun receives sunlight continuously for 6 months and the pole away from the sun experiences night for 6 months.
Question 2 A: Tick the correct answer.
The movement of the earth around the sun is known as
A. Rotation
B. Revolution
C. Inclination
Answer
The movement of the earth around the sun in a fixed path or orbit is known as a Revolution. It takes 365 days (one year) to revolve around the sun. We consider a year as consisting of 365 days only and ignore six hours for the sake of convenience.
Question 2 B: Tick the correct answer.
Direct rays of the sun fall on the equator on
A. 21 March
B. 21 June
C. 22 December
Answer
On 21st March and September 23rd, direct rays of the sun fall on the equator. At this position, neither of the poles is tilted towards the sun; so, the whole earth experiences equal days and equal nights. This is called an equinox.
Question 2 C: Tick the correct answer.
Christmas is celebrated in summer in
A. Japan
B. India
C. Australia
Answer
Due to the revolution of the earth on its axis, the Southern hemisphere receives direct sunlight in the month of December and experiences Summer Solstice.
Question 2 D: Tick the correct answer.
Cycle of the seasons is caused due to
A. Rotation
B. Revolution
C. Gravitation
Answer
Due to the revolution of the earth on its axis, the position of the earth around the sun changes. This causes seasons to change.
Question 3: Fill in the blanks.
(a) A leap year has______number of days.
(b) The daily motion of the earth is______.
(c) The earth travels around the sun in_______orbit.
(d) The sun's rays fall vertically on the Tropic of_______on 21st June.
(e) Days are shorter during______season.
Answer
(a) A leap year has 366 number of days.
A year which has 366 days and not 365 1/4 days is called a leap year.
(b) The daily motion of the earth is rotation.
Rotation can be defined as the movement of the earth on its axis in 24 hours.
(c) The earth travels around the sun in an elliptical orbit.
The shape of the earth's orbit is not round but elliptical. The earth travels around the sun in an elliptical orbit.
(d) The sun's rays fall vertically on the Tropic of Cancer on 21st June.
21st June is the longest day, also known as the Summer Solstice. On this day the sun's rays fall directly over the Tropic of Cancer.
(e) Days are shorter during winter season.
The days are shorter in winter than in summer, because of the tilt of the earth's axis.