Hi Everyone!! This article will share Motions of The Earth Questions & Answers.
In my previous post, I have shared Objective Type Questions & Answers of Motions of The Earth so, you can check this post as well.
Motions of The Earth Questions & Answers
Question 1: Define the following:
(a) Earth’s axis
Answer: An imaginary line joining north and south poles is called earth’s axis.
(b) Inclination
Answer: The earth is tilted at an angle of 23 1/2o. This tilt is called inclination.
(c) Circle of illumination
Answer: The imaginary line that divides the surface of the earth into day and night is called Circle of illumination.
(d) Perihelion
Answer: When the distance between the Sun and the Earth is minimum i.e. 147 million km on January 4, then the Earth is said to be in Perihelion.
(e) Aphelion
Answer: When the distance between the Sun and the Earth is maximum i.e. 152 million km on July 4, then the Earth is said to be in Aphelion.
(f) Earth Day
Answer: The earth takes 24 hours to complete one rotation, thus the time taken by the earth is called the Earth Day or the Solar Day.
(g) Oblate Spheroid
Answer: Rotation causes bulging of the earth near the equator and flattens the poles. This shape of the earth is called Oblate Spheroid.
Question 2: What did Nicolaus Copernicus state?
Answer: Nicolaus Copernicus stated that the Earth revolves round the Sun.
Motions of The Earth Questions & Answers
Question 3: Give reasons:
(a) The Poles experience about six months of day and six months of the night.
Answer: The revolution of the earth on its inclined axis around the sun causes longer days in summer than in winter, and longer nights in winter than in summer. The variation between the length of the day and the night is minimum at the equator. This variation gradually increases towards the poles. Hence, the Poles experience about six months of day and six months of the night.
(b) In a leap year, February has 29 days instead of 28 days.
Answer: The earth takes 365¼ days to complete one revolution around the sun. For our convenience, we consider a year equal to 365 days. The remaining ¼ day (24 hours÷ 4= 6 hours) is combined, to make one complete day of 24 hours. This extra day is added to the month of February every fourth year. Hence, in a leap year, February has 29 days instead of 28 days.
Question 4: Answer the following questions:
(a) Where does the north end of Earth’s axis lean during the Winter Solstice?
Answer: The north end of Earth’s axis leans away from the Sun during the winter (December) Solstice.
(b) Which season is it in the northern hemisphere and the southern hemisphere during the Winter Solstice?
Answer: It is winter season in northern hemisphere and summer season in southern hemisphere.
(c) What can be said about the distribution of sunlight during the Autumnal Equinox?
Answer: The solar radiation is equally distributed at this time.
(d) Which season is it in the northern hemisphere and the southern hemisphere during the Summer Solstice?
Answer: Summer in northern hemisphere and winter in southern hemisphere.
Motions of The Earth Questions & Answers
Question 5: Write short notes on:
(a) Leap Year
The Earth takes 365 ¼ days to complete one revolution around the sun. For our convenience, we consider a year equal to 365 days. The remaining ¼ day is compiled to make one complete day of 24 hours i.e. (24 hours / 4 = 6 hours). This extra day is added to the month of February every fourth year. This year is known as a leap year. In a leap year, February has 29 days instead of 28 days.
(b) Seasons
The seasons occur due to the revolution of the earth. There are mainly 4 seasons- spring, summer, autumn and winter. The seasons occur due to four different position of the earth. These positions of the earth are named based on the season experienced in the Northern Hemisphere at that particular time of the year.
(c) Spring Equinox
The sunrise falls vertically on the equator, causing equal days and nights all over the Earth The northern hemisphere has blooming spring while the southern hemisphere has chilly autumn. This occurs on 21st March.
(d) Summer Solstice
The day is referred to as being the longest day and the shortest night in the Northern hemisphere. Due to inclination of the Northern Hemisphere towards the sun, the vertical rays directly fall on the Tropic of Cancer and slanting rays fall on the Tropic of Capricorn. Thus, it is summer in the Northern hemisphere and winter in the Southern hemisphere. This position of the Earth is known as ‘Summer Solstice’. This happens on the 21st of June.
(e) Autumnal Equinox
On 23rd September, the sun again shines vertically over the equator. The duration of days and nights in both the hemispheres are equal. The seasons are just reversed, the Northern hemisphere has autumn and the southern hemisphere has spring. This is termed as ‘Autumnal Equinox’.
(f) Winter Solstice
In this position of the earth, vertical sunrise fall on Tropic of Capricorn and slanting rays falls on Tropic of Cancer. The Northern hemisphere has winter with shorter days while the southern hemisphere enjoys summer with longer days. This is known as ‘Winter Solstice’. 22nd December is the longest day in the Southern hemisphere.
Question 6: What is earth’s revolution? List four effects of earth’s revolution.
Answer: Revolution is the movement of the earth around the sun on a fixed orbit. Effects of the Earth’s revolution are:
i. Leap Year
ii. Occurrence and change of seasons
iii. Variation in the length of days and nights
iv. Distribution of heat over the earth
Motions of The Earth Questions & Answers
Question 7: What are the effects of rotation?
Answer: The effects of rotation are:
i. It causes days and nights in an alternate pattern at all places on the surface of the earth.
ii. High tides and low tides occur twice in a day due to rotation.
iii. The deflection of wind or ocean currents takes place. The deflection takes place towards its right in the northern hemisphere and towards its left in the southern hemisphere.
iv. Rotation causes bulging of the earth near the equator and flattens the poles. This is called Oblate spheroid.
v. The sun rises in the east and sets in the east.
Question 8: Why is it extremely hot at the equator?
Answer: It is extremely hot at the equator as that part of the earth receives vertical rays of the sun. The poles receive slanting rays thus it is freezing cold at the North Pole and South Pole.
Question 9: How does the revolution of the earth cause variations in the length of days and nights?
Answer: The revolution of the Earth on its inclined axis around the sun causes longer days in summer than in winter. The variation between the lengths of the day and the night is minimum at the equator. It increases gradually towards the poles. Thus, the North Pole and the South Pole experience 6 months daylight and 6 months night.
Question 10: Differentiate between Solstice and Equinox Solstice.
Answer:
| Solstice | Equinox Solstice |
| Solstice refers to the time when the sun reaches its highest or lowest point in the sky at noon, resulting in the shortest and longest days of the year. | Equinox refers to time when the sun crosses the plane of the earth’s Equator, making night and day of the equal length. |
| The word Solstice is derived from the Latin words ‘Sol’ meaning ‘sun’ and ‘Sistere meaning ‘to stand still’. | The word Equinox is derived from the Latin words ‘aequus’ meaning ‘equal’ and ‘nox’ meaning ‘night’. |
| It happens twice a year on June 21 (summer solstice) and December 22 (winter solstice). | It happens twice a year around March 21 (spring equinox) and September 23 (autumnal equinox). |
| It happens during summer and winter. | It happens at the start of spring and autumn. |