NCERT Solutions for Class 7 Science Curiosity Chapter 12 PDF Download

NCERT Solutions for Class 7 Science Curiosity Chapter 12 are designed as per the latest CBSE class 7 science syllabus to help students understand the concepts of celestial bodies like the Earth, Moon, and the Sun.

 These solutions cover all the textbook exercises and in-text questions clearly and simply, making it easier for students to grasp how day and night occur, why seasons change, and how eclipses happen. 

NCERT Solutions for Class 7 Science Curiosity Chapter 12 Earth, Moon and the Sun

Class 7 Science Curiosity Chapter 12 NCERT, titled The Earth, Moon, and the Sun, focuses on how these three celestial bodies influence life on Earth. The chapter helps students understand how the rotation of the Earth causes day and night, how its revolution around the Sun leads to seasonal changes, and how the Moon’s position results in phases and eclipses.

Through easy explanations and real-life activities, Chapter 12 of Class 7 Science helps learners understand the science behind what we see in the sky every day and night. These concepts build a strong base for astronomy and environmental science, making this chapter both exciting and informative.

Class 7 Science Chapter 12 Question Answer

Below are accurate, easy-to-understand science chapter 12 class 7 question answer resources from the NCERT textbook:

Activity 12.1: Let us explore 

 Sit on a merry-go-round facing towards the outer side as shown in Fig. 12.1. Fig. 12.1: A girl observing objects around her while riding a merry-go-round  Ask someone to turn the merry-goround slowly in the anti-clockwise direction as shown in Fig. 12.1.

While you are sitting on the moving merrygo-round, look around you. Do the objects around you appear to be moving? In which direction do they appear to be moving? 

While you turn in the anti-clockwise direction, the objects appear to turn around you in the opposite direction, that is, in the clockwise direction. 

 Now fi x your gaze at a particular tree (or a building) ahead of you while sitting on the merry-go-round turning around in an anti-clockwise direction. In which direction do you find the tree turning around you? Is it in your view all the time?

Answer: 

Observation 1:
When you sit on a merry-go-round facing outward and it moves anti-clockwise, the objects around you appear to move in the opposite direction, i.e., in the clockwise direction. This is because while you are rotating, your perspective changes, creating an illusion of motion in the surrounding objects.

Observation 2:
When you fix your gaze at a particular tree (or building) while the merry-go-round moves anti-clockwise:

• The tree appears to turn around you in the clockwise direction.

• The tree is not in your view all the time; it comes in and goes out of your sight as the merry-go-round rotates.

Conclusion:

This activity helps you understand that when you are on a rotating object (like the Earth), stationary objects around you appear to move in the opposite direction. Similarly, the Sun appears to move from east to west because the Earth rotates from west to east.

Activity 12.2: Let us explore

Use a globe to represent the Earth and place a small sticker to mark your location on it (Fig. 12.4a).  While viewing from above the North Pole, slowly rotate the globe on its axis in anti-clockwise direction. 

Observe how your location turns around and finally comes back to its original position completing one rotation.

Use a torch to represent the Sun. Go to a relatively dark room to carry out the further steps of the activity.

 Now, shine light from the torch placed at some distance, say 1.5 metres, on the globe as shown in Fig. 12.4b. Do you notice how half of the globe receives the light from the torch, while the other half stays dark? 

Answer:

Part 1: Understanding Earth's Rotation

• When you rotate the globe anti-clockwise (viewed from above the North Pole), you will observe that the sticker (your location) moves around the globe and returns to its original position after one full rotation.

• This demonstrates that rotation is the movement of an object where all its parts move around an imaginary line called the axis of rotation.

Conclusion:
The Earth rotates on its axis from west to east. As it completes one full rotation in about 24 hours, it causes the cycle of day and night.

Part 2: Understanding Day and Night Using a Torch and Globe

• In a dark room, when a torch (Sun) is shined on the globe (Earth) from a distance, only half of the globe receives light.

• The half that faces the torch is in daylight, while the other half, which is not lit, remains in darkness (night).

Conclusion:
This part of the activity shows how day and night occur on Earth. The side facing the Sun experiences day, and the side away from the Sun experiences night. As the Earth rotates, different places move into light and out of it, creating a regular day-night cycle.

Activity 12.3: Let us explore

On an early evening between March and May, identify the Big Dipper (Saptarishi), and the Pole Star (Dhruva Tara), if visible, as you did in the chapter ‘Beyond Earth’ in the Grade 6 Science textbook Curiosity.  

Note down your location and date of your night sky observations. The activity must be carried out on the same night.

Draw the orientation of the Big Dipper in the sky with respect to the Pole Star (or a fi xed tree/building on the ground in a direction towards the Big Dipper if you cannot see the Pole Star). Mark the time of your observation along with your sketch as shown in Fig. 12.7. 

After two hours, observe the Big Dipper again. Has it moved? Again, draw its orientation and note down the time.  Repeat the above step after two hours. Do you observe that the Big Dipper appears to move around the Pole Star (notice just the movement even if you cannot see the Pole Star)? 

Answer:  

This activity helps you observe the apparent motion of stars in the night sky due to the rotation of the Earth.

Step-by-Step Observations:

1. Initial Observation (Evening, March–May):

• You spot the Big Dipper (Saptarishi) and, if possible, the Pole Star (Dhruva Tara).

• Note down your location, date, and time of observation.

• Sketch the position of the Big Dipper in the sky to a fixed reference point (like a tree or building).

• This first sketch shows the starting orientation.

2. Second Observation (After 2 Hours):

• Look at the Big Dipper again.

• You’ll notice it has changed position in the sky.

• Draw another sketch and note the new time

• The Big Dipper seems to have rotated around the Pole Star, moving anti-clockwise (as seen from Earth’s surface in the Northern Hemisphere).

3. Third Observation (After Another 2 Hours)

• Observe and sketch the new orientation again.

• You’ll find that the Big Dipper keeps moving in a circular path around the Pole Star (even if you can’t see the Pole Star, you’ll notice the arc-like shift).

Conclusion:

• The Big Dipper appears to move in the sky throughout the night.

• This movement is not real; it is apparent, caused by the rotation of the Earth from west to east.

• The Pole Star appears fixed, while other stars like the Big Dipper seem to rotate around it.

Activity 12.4: Let us explore 

 Ask your friend to stand in front of you at a distance of about 5 metres. Consider his head to be the Sun.  Now close one eye and show a thumbs up with your outstretched hand towards your friend as shown in Fig. 12.12. Are you able to cover the entire head of your friend with your thumb?

Answer:

Observation:

• When your friend is standing about 5 metres away from you and you stretch out your arm, showing a thumbs up, and close one eye, you will most likely be able to cover your friend’s entire head (which represents the Sun) with just your thumb.

Conclusion:

Even though your friend’s head (the Sun) is much larger than your thumb (representing the Moon), you are still able to cover it completely with your thumb because:

• Your thumb is closer to your eye.

• Your friend is farther away.

This shows that the apparent size of an object depends on both its actual size and its distance from the observer.

Earth Moon and the Sun Class 7 Question Answer (InText)

Question 1.  How day and night occur on the Earth due to its rotation?
Answer: Rotation

Question 2.  Since the Earth is rotating, shouldn’t the stars also appear to move in the sky like the Sun?
Answer: Yes

Question 3.  Why do different stars appear in the night sky over the course of a year?
Answer: Revolution

Question 4.  We go through a cycle of seasons every year. Is it related to the revolution of the Earth around the Sun in some way?
Answer: Yes

Question 5.  Why are days longer in summer than in winter?
Answer: Tilt

Question 6.  Could the light from the Sun get blocked by the two planets which are revolving between the Earth and the Sun?
Answer: No

Let Us Enhance Our Learning: NCERT Exercises

These chapter 12 class 7 science questions deepen understanding:

Question 1.
In Fig. 12.17, how many hours of sunlight do the North Pole and the South Pole receive during one rotation of the Earth?

Answer:
In the given figure, North Pole: 0 hours
South Pole: 24 hours

Question 2.
Fill in the blanks
(i) Stars rise in the ______ and set in the _______.
Answer:
east, west

(ii) Day and night are caused by the Earth’s _______
Answer:
rotation

(iii) When the Moon fully covers the Sun from our view, it is called a _______ solar eclipse.
Answer:
total

Question 3.
State whether True or False
(i) Lunar eclipse occurs when the Sun comes between the Earth and the Moon.
Answer:
False

(ii) Sunrise happens earlier in Gujarat than in Jharkhand.
Answer:
False

(iii) In Chennai, the longest day occurs on the summer solstice.
Answer:
False

(iv) We should watch the solar eclipse directly with our naked eye spherical shape.
Answer:
False

(vi) The Earth’s revolution around the Sun causes day and night.
Answer:
False

Question 4.
Padmashree saw the Orion constellation nearly overhead at 8 pm yesterday. When will she see Orion overhead today?
Answer:

The stars appear to rise about 4 minutes earlier each day due to the Earth's revolution around the Sun. This is because as the Earth moves in its orbit, our night-time view of the sky gradually shifts. So, if Padmashree saw the Orion constellation at 8:00 pm yesterday, she will see it overhead at around 7:56 pm today.

Question 5

Nandhini saw a group of stars rising at midnight on 21 June. When will she see the same group of stars rising at midnight next year?
Answer:
Since the stars rise about 4 minutes earlier each day, this shift accumulates to about 24 hours over a year. That’s why the same group of stars will rise at midnight exactly one day earlier the next year. So, Nandhini will see the same stars rising at midnight on 20 June next year.

Question 6

Abhay noticed that when it was daytime in India, his uncle who was in the USA was generally sleeping as it was night-time there. What is the reason behind this difference?
Answer:
This happens because of the rotation of the Earth, which leads to the creation of different time zones. As the Earth rotates from west to east, different parts of the Earth experience day and night at different times. Since India is ahead of the USA in time, it is daytime in India while it is still night time in the USA.

Question 7.
Four friends used the following ways to see the solar eclipse. Who among them was being careless?
(i) Ravikiran used a solar eclipse goggle.
(ii) Jyothi used a mirror to project the Sun’s image.
(iii) Adithya saw the Sun directly with his eyes.
(iv) Aruna attended a programme arranged by a planetarium.
Answer:
(iii) Adithya was being careless because he looked directly at the Sun with his naked eyes. This is dangerous and can cause permanent damage to eyesight.
The safe methods to view a solar eclipse include:

• Using solar eclipse goggles (like Ravikiran),

• Using indirect projection methods (like Jyothi), and

• Attending planetarium programmes with proper guidance (like Aruna).

Question 8.
The Moon is much smaller than the Sun, yet it can block the Sun completely from our view during a total solar eclipse. Why is it possible?
Answer:
Though the Moon is much smaller than the Sun, it appears to be almost the same size in the sky because it is much closer to the Earth than the Sun.

• The Sun is about 400 times bigger than the Moon.

• But it is also about 400 times farther away.
  This perfect size-distance ratio makes the Moon capable of covering the Sun completely during a total solar eclipse, making it look dark even during daytime.

Question 9.
The Indian cricket team matches in Australia are often held in December. Should they pack winter or summer clothes for their trip?
Answer:
They should pack summer clothes.
This is because Australia lies in the Southern Hemisphere, where the seasons are opposite to those in the Northern Hemisphere (India). So while it is winter in India during December, it is summer in Australia at that time. Therefore, the team should be prepared for hot and warm weather.

Question 10.
Why do you think lunar eclipses can be seen from a large part of the Earth when they happen, but total solar eclipse can be seen by only a small part of the Earth?
Answer:
A lunar eclipse occurs when the Earth's shadow falls on the Moon.

• The Earth's shadow is very large, so the eclipse can be seen by everyone on the night side of the Earth.

• It also lasts longer.

In contrast, during a total solar eclipse, the Moon's shadow falls on the Earth.

• Since the Moon is much smaller, its shadow covers only a narrow path on the Earth's surface.

• This makes the total solar eclipse visible to only a small area and for a short time.

Question 11.
If the Earth’s axis were not tilted with respect to the axis of revolution, explain what would be the effect on seasons?
Answer:
If the Earth’s axis were not tilted, there would be no seasons.

• Every place on Earth would receive equal sunlight throughout the year.

• This means the weather would remain the same year-round — no summer, winter, spring, or autumn.

• Also, days and nights would be of equal length every day everywhere on Earth.

Class 7 Science Curiosity Chapter 12 Question Answer PDF Download

Students can download the NCERT Solutions for Class 7 Science Curiosity Chapter 12 in PDF format from the link given below. Downloading the PDF allows students to access well-structured question answers anytime, offline for effective revision and exam preparation.

Benefits of Using NCERT Solutions for Class 7 Science Curiosity Chapter 12  Earth, Moon and the Sun

The solutions provide clear and simple explanations of complex topics like the Earth's rotation and revolution, eclipses, time zones, and seasons, helping students understand them easily.

These answers are prepared strictly according to the latest NCERT syllabus and guidelines, ensuring students learn only what is relevant for exams.

By practising these question-answers, students can strengthen their understanding and perform better in class tests, assignments, and final exams.

The concise format of the solutions makes it perfect for quick revision before exams, especially when time is limited.