Students rely on Class 7 Science Extra Questions and Class 7th Curiosity Chapter 12 Earth Moon and the Sun Important Extra Question Answer to improve their grades.
Class 7 Science Chapter 12 Earth Moon and the Sun Extra Questions
Class 7 Science Chapter 12 Extra Questions on Earth Moon and the Sun
Earth Moon and the Sun Class 7 Very Short Question Answer
Question 1.
What is rotation?
Answer:
Rotation is the motion of an object in which all its parts move in circles around an imaginary line that passes through it.
Question 2.
What is axis of rotation?
Answer:
The imaginary line in an object around which it rotates is called the axis of rotation.
Question 3.
Who used a long pendulum to give the first simple demonstration of the Earth’s rotation?
Answer:
In the middle of nineteenth century Leon Foucault, a known scientist, used a long pendulum to give the first simple demonstration of the Earth’s rotation.
Question 4.
What are the dates of the year when the Sun rises and falls on the Poles of the Earth?
Answer:
At the North Pole, the Sun rises in the East direction on 21 March and sets on 22 September. Then the Sun rises at the South Pole and sets on 21 March.
Question 5.
What is solar eclipse?
Answer:
When the Moon comes in between the Sun and the Earth in a way that obstructs the light from the Sun from reaching us. This is known as a solar eclipse.
Earth Moon and the Sun Class 7 Short Question Answer
Question 1.
What is not the correct explanation of the causes of seasons on the Earth?
Answer:
It is wrong to say that changes of seasons are caused due to elliptical shape of the orbit and that the Sun is closer to the Earth during certain periods compared to others. Also, the Northern Hemisphere being closer to the Sun in June due to tilt in the axis does not make much difference in seasons.
Question 2.
Why pole star appears stationary when seen from the Earth?
Answer:
The Earth’s axis of rotation points very close to the Pole Star in the Northern Hemisphere. Therefore, the Pole Star appears nearly stationary in the sky from the Earth.
Question 3.
What do you know about summer solstice?
Answer:
In the Northern Hemisphere, the longest day occurs around 21 June— this is known as summer solstice.
Question 4.
What is winter solstice?
Answer:
The shortest day and longest night in this Hemisphere occur around 22 December known as the winter solstice.
Question 5.
Are the Spring equinox and Autumn equinox same?
Answer:
No, these are not the same. Around 21 March and 23 September, the daytime lasts for 12 hours. In the Northern Hemisphere, these days are called the spring equinox and the autumn equinox.
Earth Moon and the Sun Class 7 Long Question Answer
Question 1.
Explain the phenomenon that gives rise to the seasons.
Answer:
- The tilt of the Earth’s axis and the spherical shape of the Earth gives rise to seasons.
- In June, the Northern Hemisphere is tilted towards the Sun while the Southern Hemisphere is tilted away from the Sun.
- The sunrays are spread in a smaller area in the Northern Hemisphere due to the spherical shape of the Earth’s surface. So that area is heated more.
- The Northern Hemisphere receives sunlight for more than 12 hours in June, thus, experiences more intense sunlight, which lasts for a longer time, causing the summer season.
- In December, the Northern Hemisphere receives sunlight for less time and also the sunrays are spread in a larger area. So, the area is heated less compared to the Southern Hemisphere. There is winter on the Northern Hemisphere in December.
- The situation is reverse at the Southern Hemisphere. There is winter in June and summer in December.
Question 2.
Explain the phenomenon of rotation of the Earth in detail.
Answer:
- The Earth spins (or rotates) on its own axis in space. ‘The Earth’s axis of rotation passes through its geographic North Pole and the South Pole.
- The Earth’s axis of rotation is not upright with respect to the orbit, but is tilted.
- The Earth completes one rotation . in about 24 hours.
- When viewed from the top of the North Pole the Earth is rotating in the anti-clockwise direction, that is, from West to East.
- The Earth’s rotation from West to East causes the day-night cycle. The side facing the Sun experiences daytime, while the other side is dark and experiences night.
- It is due to the rotation of the Earth, that the Sun appears to rise in the eastward direction. It moves across the sky from the East to the West and sets in the westward direction.
- When the Sun sets the night begins and the stars become visible in the sky.
Question 3.
What is solar eclipse? Explain the difference between total solar eclipse and partial solar eclipse.
Answer:
- When the Moon comes in between the Sun and the Earth in a way that obstructs the light from the Sun from reaching us. This is known as a solar eclipse.
- The shadow of the Moon falls on a small area on the surface of the Earth. This area is in total darkness, as no part of the Sun can be seen from there. This is called a total solar eclipse.
- In areas where the Moon partially blocks out only some regions of the Sun, we see a partial solar eclipse.
- The total solar eclipse is visible only for a few minutes. As the Moon begins to move away from the front of the Sun), we see a partial solar eclipse and daylight begins to return.
Question 4.
What precautions should we take while viewing a solar eclipse?
Answer:
Viewing the Sun directly even during the eclipse, the Sun is intense enough to damage the eyes and cause blindness. Thus, directly viewing solar eclipse or viewing it through sunglasses, binoculars, or telescopes must be strictly avoided.
Usually, astronomy organisations, such as planetaria and astronomy clubs hold eclipse viewing events during a solar eclipse. Participating in such events is the best way to observe a solar eclipse since the organisers not only provide specialised eye protection for solar viewing, but also offer scientific explanations.
Earth Moon and the Sun Class 7 Case Based Questions
I. During a total solar eclipse, for a few minutes it turns dark during the day as no sunlight reaches the Earth. Due to the Earth’s rotation and the motion of the Moon in its orbit, the Moon’s shadow moves across the surface of the Earth. Thus, the total solar eclipse is visible only for a few minutes.
Answer the following Questions:
Question 1.
Why the total solar eclipse is insible only for a few minutes?
Answer:
Due to the Earth’s rotation and the motion of the Moon, the shadow made by the Moon on the Earth’s surface , moves away, the total solar eclipse thus ‘ ends in a few minutes.
Question 2.
What precautions should we take to sight a solar eclipse?
Answer:
We must avoid seeing the Sun directly with our eyes. We should make arrangements of casting the image of the Sun on a screen with a mirror and see the image of the Sun on the screen.
We should not see the Sun through the mirror also.
We should not view it through sunglasses, binoculars, or telescopes.
Or we should attend the show by the astronomical organisations where they show the Sun during eclipse with all precautions and give more knowledge related to the eclipses.
Question 3.
What are the superstitions associated with the Solar eclipse?
Answer:
When the reasons of blockage of sunlight were not known, the superstitions like, not cooking, eating or even not moving out of the houses were common.
II. Every evening the Sun sets in the westward direction and the night sky becomes visible. We know that this occurs due to the Earth’s rotation. As the Earth also revolves around the Sun continuously, the stars seen in the night sky after sunset gradually change over a year as we look in different directions.
Answer the following questions:
Question 1.
Why do different stars appear in the night sky over the course of a year?
Answer:
The revolution of the Earth around the Sun makes the difference in viewing the night sky. One revolution of the Earth completes in nearly one year. It is after complete one year that we can observe the same stars at the same time in the night sky.
Question 2.
Why pole star is used to find directions?
Answer:
Axis of the Earth points nearly to the Pole Star from the northern hemisphere. The pole star appears stationary from the Earth and all other stars appear to move around it during the night. This gives an idea of direction to the navigators during the night.
Earth Moon and the Sun Extra Questions for Practice
Very Short Answer Type Questions
Question 1.
In what time does the Earth complete one rotation around its axis?
Question 2.
What is the period of time in which the Earth completes one revolution around the Sun?
Question 3.
Viewed from above what is the shape of Earth’s orbit around the Sun?
Question 4.
If it is day in India, is it day or night in USA?
Question 5.
We have summers in June and winters in December in India? Is it the same for Australia?
Short Answer Type Questions
Question 1.
Why do we not need any precautions to view a lunar eclipse like the ones we take in viewing a solar eclipse?
Question 2.
How do days and nights cycles occur on the Earth?
Question 3.
Changes of seasons are caused due to elliptical shape of the orbit and that the Sun is closer to the Earth during certain periods compared to others. Do you agree?
Question 4.
The days and nights are nearly equal to 12 hours on two days in a year on the Northern Hemisphere. What are these days called?
Question 5.
What is the smallest day and the largest day on the Northern hemisphere called?
Long Answer Type Questions
Question 1.
If you observe the Big Dipper on a clear night in the month of April every 2 hours starting from 8:00 p.m. Draw the orientation of the Big Dipper in the sky with
respect to the Pole Star. Mark the time of your observation along with your sketch.
Question 2.
What is Lunar eclipse? Explain the difference between total lunar eclipse and partial lunar eclipse.
Question 3.
Draw a diagram to show total and partial lunar eclipses.
Case-Based Questions
When the Moon is completely in the Earth’s shadow, it is called a total lunar eclipse. The bright disc of the Moon starts to appear dark red in colour and stays that way until the Moon moves out of the shadow of the Earth. When part of the Moon is in the Earth’s shadow and the rest of the Moon is visible, it’is called a partial lunar eclipse. Unlike the Sun, we can safely watch the eclipsed full Moon with our naked eye.
Answer the following questions:
Question 1.
How is lunar eclipse formed?
Question 2.
How the lunar eclipse is different from the solar eclipse?
Multiple Choice Questions (MCQs)
Choose the correct option in the following questions
Question 1.
The Rotation of the Earth on its axis and the Revolution of the Earth in its orbit completes in respectively.
(a) 365 days and 20 hours
(b) 365 days, 6 hours and 24 hours
(c) 24 hours and 365 days, 6 hours
(d) 20 hours and 360 days
Question 2.
The seasons on the Earth are NOT caused by
(a) Tilt of the axis of the Earth
(b) Spherical shape of the Earth
(c) Spreading of Sun’s rays on a small or a large area
(d) Rotation of the Earth on its axis
Question 3.
The Moon comes in between the Sun and the Earth to block light of the Sun completely on a certain area on the Earth. This causes
(a) Total lunar eclipse
(b) Total solar eclipse
(c) Partial solar eclipse
(d) Partial lunar eclipse
Question 4.
The Earth completes on revolution around the Sun in 365 days 6 hours. The statement is
(a) True
(b) False
(c) Partially true
(d) Irrelevant
Question 5.
The rotation of the Earth is
(a) Clockwise in direction
(b) West to East in direction
(c) East to West in direction
(d) Anticlockwise during the day and clockwise during the night
Assertion-Reason Questions
Directions: Each of the questions (i) and (ii) contain two statements – first ‘Assertion’ and second ‘Reason’. Select the correct answer to these questions from the codes (a), (b), (c) or (d) as given below:
(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are true and Reason is NOT the correct explanation of Assertion.
(c) Assertion is true and Reason is false.
(d) Assertion is false and Reason is true.
(i) Assertion (A): The days and nights on the Earth are always equal.
Reason (R): The polar regions experience continuous sunshine for six months followed by a six-month period of darkness.
(ii) Assertion (A): Revolution of the Earth around the Sun causes the seasons on the Earth.
Reason (R): The tilt of the Earth’s axis and the spherical shape of the Earth gives rise to seasons.
Fill in the Blanks
(a) The Earth, like all other ______ revolves around the Sun.
(b) If viewed from the top the orbit of the Earth around the Sun is nearly ______
(c) The Earth completes one revolution around the Sun in about ______ days and 6 hours.
(d) The tilt of the Earth’s and the ______ shape of the Earth gives rise to seasons.
(e) The Earth’s axis of rotation points very close to the ______ in the Northern Hemisphere.
True or False
State whether True or False answer with reason
(i) When the Earth comes in between the Sun and the Moon, this is known as a solar eclipse.
(ii) In a solar eclipse the shadow of the Moon falls on a small area on the surface of the Earth. This area is in total darkness, as no part of the Sun can be seen from there. This is called a total solar eclipse.
(iii) Seasons on the Earth are caused by the rotation of the Earth on its axis.
(iv) Northern and Southern hemispheres differ markedly in the seasons.
(v) Spherical shape of the Earth causes rays of the Sun to spread on a’small or a large area based on the tilt of the axis.
Match the following:
Question 1.
Match the following items given in Column A with that in Column B:
| Column A | Column B |
| 1. The light of the Sun completely blocked by the Moon | (a) Pole star |
| 2. Earth’s shadow on the Moon makes the Moon only partially visible | (b) Total solar eclipse |
| 3. Tilted axis of the Earth and its spherical shape | (c) Rotation and revolution time of the Earth |
| 4. Star looking stationary in the night sky | (d) Cause of seasons |
| 5. 24 hours and 365 days and 6 hours | (e) Total lunar eclipse |