✅ True or False (10 Questions)

(Class 8 CBSE Standard – Good Quality)

1. The Moon shines because it reflects sunlight falling on its surface.
   True hecu111
2. The phases of the Moon occur because the Moon changes its shape every night.
   False
   (The Moon’s shape does not change; only the visible illuminated part changes.) hecu111
3. The day when the Moon is not visible from Earth is called the New Moon day (Amavasya).
   True hecu111
4. The period during which the bright portion of the Moon decreases is called the waning period (Krishna Paksha).
   True hecu111
5. A waxing Moon is easiest to observe at sunrise.
   False
   (A waxing Moon is easiest to spot at sunset, while a waning Moon is easier at sunrise.) hecu111
6. The Moon rises at the same time every day just like the Sun.
   False
   (Moonrise happens about 50 minutes later each day.) hecu111
7. The phases of the Moon are caused by Earth’s shadow falling on the Moon.
   False
   (Earth’s shadow causes lunar eclipse, not phases.) hecu111
8. A complete cycle of Moon phases takes about 29.5 days, which forms the basis of a month.
   True hecu111
9. Leap years are added in the Gregorian calendar to keep the calendar synchronised with seasons.
   True hecu111
10. Artificial satellites are launched to help in communication, navigation, weather monitoring, and research.
    True hecu111

✅ Fill in the Blanks (10 Questions)

(Class 8 CBSE Standard – Good Quality)

1. The Moon does not emit its own light; it shines by reflecting __________.
   Answer: sunlight hecu111
2. The changing shapes of the bright portion of the Moon are called the __________ of the Moon.
   Answer: phases hecu111
3. The day when the Moon appears as a complete bright circle is called the __________ Moon day (Purnima).
   Answer: full hecu111
4. The day when the Moon is not visible is called the __________ Moon day (Amavasya).
   Answer: new hecu111
5. The period during which the bright part of the Moon decreases is called the __________ period.
   Answer: waning hecu111
6. The period during which the bright part of the Moon increases is called the __________ period.
   Answer: waxing hecu111
7. The Moon rises about __________ minutes later each day.
   Answer: 50 hecu111
8. A complete cycle of Moon phases takes about __________ days.
   Answer: 29.5 hecu111
9. The Gregorian calendar is a __________ calendar based on the cycle of seasons.
   Answer: solar hecu111
10. An extra day added every four years in a calendar is called a __________ day.
    Answer: leap

✅ Multiple Choice Questions (15 MCQs)

(Good Quality CBSE Pattern)

1. The Moon shines because it:

A. Produces its own light
B. Reflects sunlight
C. Burns gases on its surface
D. Receives light from stars
✅ Answer: B hecu111

2. The changing shapes of the bright part of the Moon are called:

A. Shadows
B. Lunar months
C. Phases of the Moon
D. Solar eclipses
✅ Answer: C hecu111

3. The two-week period during which the bright part of the Moon decreases is called:

A. Waxing period
B. Waning period
C. Solar cycle
D. Rotation period
✅ Answer: B hecu111

4. The day when the Moon is not visible is called:

A. Full Moon
B. Half Moon
C. New Moon
D. Gibbous Moon
✅ Answer: C hecu111

5. The Moon appears as a full bright circle on:

A. Amavasya
B. Purnima
C. Eclipse day
D. Crescent day
✅ Answer: B hecu111

6. The waxing period of the Moon in India is called:

A. Krishna Paksha
B. Shukla Paksha
C. Adhika Maasa
D. Sidereal year
✅ Answer: B hecu111

7. A waning Moon is easiest to spot at:

A. Sunrise
B. Noon
C. Midnight
D. Sunset
✅ Answer: A hecu111

8. The Moon rises about ______ minutes later each day.

A. 10
B. 25
C. 50
D. 100
✅ Answer: C hecu111

9. The phases of the Moon occur because:

A. The Moon changes its shape
B. Earth’s shadow falls on the Moon
C. We see different illuminated portions as the Moon revolves
D. The Moon rotates very fast
✅ Answer: C hecu111

10. A lunar eclipse happens when:

A. The Sun blocks the Moon
B. Earth’s shadow falls on the Moon
C. Moon’s shadow falls on Earth
D. Stars cover the Moon
✅ Answer: B hecu111

11. The cycle of Moon phases takes about:

A. 7 days
B. 15 days
C. 29.5 days
D. 365 days
✅ Answer: C hecu111

12. The Gregorian calendar is a:

A. Lunar calendar
B. Solar calendar
C. Luni-solar calendar
D. Star calendar
✅ Answer: B hecu111

13. Leap years are introduced because:

A. The Moon revolves faster
B. Earth takes extra time to revolve around the Sun
C. Months are too short
D. Seasons do not exist
✅ Answer: B hecu111

14. The Indian National Calendar begins on:

A. 1 January
B. 21 June
C. 22 March
D. 15 August
✅ Answer: C hecu111

15. Artificial satellites are launched mainly for:

A. Changing Moon phases
B. Increasing rainfall
C. Communication, navigation, and weather monitoring
D. Creating eclipses
✅ Answer: C

✅ Assertion–Reason Questions (10)

(CBSE Class 8 Standard – Good Quality)

Directions: Choose the correct option:

A. Both A and R are true and R is the correct explanation of A
B. Both A and R are true but R is not the correct explanation of A
C. A is true but R is false
D. A is false but R is true

1.

Assertion (A): The Moon does not have its own light.
Reason (R): The Moon shines because it reflects sunlight.
✅ Answer: A hecu111

2.

Assertion (A): The phases of the Moon occur because the Moon changes its shape.
Reason (R): We see different portions of the illuminated Moon as it revolves around Earth.
✅ Answer: D hecu111

3.

Assertion (A): A New Moon day is called Amavasya in India.
Reason (R): On this day, the Moon is not visible from Earth.
✅ Answer: A hecu111

4.

Assertion (A): A Full Moon day is called Purnima.
Reason (R): On this day, the Moon appears as a complete bright circle.
✅ Answer: A hecu111

5.

Assertion (A): The Moon rises at the same time every day.
Reason (R): The Moon rises about 50 minutes later each day.
✅ Answer: D hecu111

6.

Assertion (A): Waxing Moon is easiest to observe at sunset.
Reason (R): During waxing, the Moon is seen in the evening sky.
✅ Answer: A hecu111

7.

Assertion (A): A lunar eclipse occurs when Earth’s shadow falls on the Moon.
Reason (R): Earth comes between the Sun and the Moon during a lunar eclipse.
✅ Answer: A hecu111

8.

Assertion (A): The Gregorian calendar is based on the Moon’s revolution.
Reason (R): It is a solar calendar based on Earth’s revolution around the Sun.
✅ Answer: D hecu111

9.

Assertion (A): Leap years are added to keep the calendar aligned with seasons.
Reason (R): Earth takes about 365¼ days to complete one revolution around the Sun.
✅ Answer: A hecu111

10.

Assertion (A): Artificial satellites are useful for communication and weather forecasting.
Reason (R): Satellites help in transmitting signals and monitoring Earth from space.
✅ Answer: A

✅ Very Short Answer Questions (10 Questions)

(2 Marks Each – CBSE Class 8 Standard, Good Quality)

1. Why does the Moon shine in the night sky?

Answer:
The Moon does not have its own light. It shines because it reflects sunlight falling on its surface. hecu111

2. What are the phases of the Moon?

Answer:
The different shapes of the bright portion of the Moon visible from Earth are called the phases of the Moon. hecu111

3. What is a New Moon day called in India?

Answer:
A New Moon day is called Amavasya in India, when the Moon is not visible. hecu111

4. What is a Full Moon day called in India?

Answer:
A Full Moon day is called Purnima, when the Moon appears as a complete bright circle. hecu111

5. What is meant by waxing of the Moon?

Answer:
Waxing refers to the period when the illuminated portion of the Moon increases from New Moon to Full Moon. hecu111

6. What is meant by waning of the Moon?

Answer:
Waning refers to the period when the illuminated portion of the Moon decreases from Full Moon to New Moon. hecu111

7. How much later does the Moon rise each day?

Answer:
The Moon rises about 50 minutes later each day compared to the previous day. hecu111

8. How long does a complete cycle of Moon phases take?

Answer:
A complete cycle of Moon phases takes about 29.5 days, which forms the basis of a lunar month. hecu111

9. Why do we have leap years in the Gregorian calendar?

Answer:
Leap years are added because Earth takes about 365¼ days to revolve around the Sun. The extra day keeps the calendar aligned with seasons. hecu111

10. Mention any two uses of artificial satellites.

Answer:
Artificial satellites are used for communication, weather forecasting, navigation, remote sensing, and scientific research.

✅ Short Answer Questions (10 Questions)

(3 Marks Each – CBSE Class 8 Standard, Good Quality)

1. Explain why the Moon shows different phases.

Answer:
The Moon revolves around Earth. As it moves, different portions of its sunlit side become visible to us. These changing visible illuminated parts are called phases of the Moon. The Moon itself does not change shape. hecu111

2. Differentiate between waxing and waning of the Moon.

Answer:
Waxing is the period when the bright portion of the Moon increases from New Moon to Full Moon. Waning is the period when the bright portion decreases from Full Moon back to New Moon. hecu111

3. Why does the Moon rise about 50 minutes later each day?

Answer:
The Moon revolves around Earth. Because of this motion, it takes extra time each day for Earth to rotate enough for the Moon to appear above the horizon, so moonrise is delayed by about 50 minutes daily. hecu111

4. What is the basis of a lunar calendar?

Answer:
A lunar calendar is based on the phases of the Moon. One lunar month is the time taken by the Moon to complete one full cycle of phases, which is about 29.5 days. hecu111

5. Why is the Gregorian calendar called a solar calendar?

Answer:
The Gregorian calendar is based on Earth’s revolution around the Sun. It follows the solar year of about 365 days and is aligned with the cycle of seasons. hecu111

6. Explain why leap years are necessary.

Answer:
Earth takes about 365¼ days to complete one revolution around the Sun. The extra ¼ day adds up to one full day every four years. Therefore, a leap year with an extra day is added to keep the calendar accurate. hecu111

7. What is a lunar eclipse?

Answer:
A lunar eclipse occurs when Earth comes between the Sun and the Moon, causing Earth’s shadow to fall on the Moon. As a result, the Moon appears partially or fully dark. hecu111

8. Mention the significance of the Indian National Calendar.

Answer:
The Indian National Calendar is officially used in India along with the Gregorian calendar. It begins on 22 March and is based on a solar system of months linked with seasons. hecu111

9. What are artificial satellites? State their importance.

Answer:
Artificial satellites are man-made objects launched into space to orbit Earth. They are important for communication, weather forecasting, navigation, remote sensing, and scientific research. hecu111

10. How do phases of the Moon help in keeping time?

Answer:
The regular cycle of Moon phases forms the basis of a lunar month. Ancient calendars were based on these cycles, helping people measure time, plan festivals, and track seasons.

✅ Case-Based Questions (4 Cases)

(4 Marks Each | Sub-questions: 1 + 1 + 2 Marks)
CBSE Competency-Based Standard

Case 1: Phases of the Moon

The Moon revolves around Earth and reflects sunlight. As the Moon moves, we see different illuminated portions of it. This causes the phases of the Moon such as crescent, half moon, and full moon.

Questions:

Q1. (1 Mark) Does the Moon produce its own light?
Answer: No, the Moon reflects sunlight. hecu111

Q2. (1 Mark) What are the changing shapes of the Moon called?
Answer: Phases of the Moon. hecu111

Q3. (2 Marks) Why do phases of the Moon occur?
Answer:
Phases occur because as the Moon revolves around Earth, different parts of its sunlit side become visible from Earth. hecu111

Case 2: Waxing and Waning

After New Moon, the bright portion of the Moon increases day by day. This is called waxing. After Full Moon, the bright portion decreases, which is called waning.

Questions:

Q1. (1 Mark) What is waxing of the Moon?
Answer: The increase in the illuminated part of the Moon. hecu111

Q2. (1 Mark) What is waning of the Moon?
Answer: The decrease in the illuminated part of the Moon. hecu111

Q3. (2 Marks) How long does a complete cycle of Moon phases take?
Answer:
A complete Moon phase cycle takes about 29.5 days, forming the basis of a lunar month. hecu111

Case 3: Calendars and Leap Year

The Gregorian calendar is widely used and is based on Earth’s revolution around the Sun. Earth takes about 365¼ days for one revolution. To adjust this extra time, leap years are introduced.

Questions:

Q1. (1 Mark) Why is the Gregorian calendar called a solar calendar?
Answer: Because it is based on Earth’s revolution around the Sun. hecu111

Q2. (1 Mark) How many extra days are added in a leap year?
Answer: One extra day. hecu111

Q3. (2 Marks) Why are leap years necessary?
Answer:
Leap years are needed because Earth takes 365¼ days to complete one revolution, and the extra quarter day adds up to one full day every four years. hecu111

Case 4: Artificial Satellites

Artificial satellites are man-made objects launched into space that orbit Earth. They have many uses such as communication, navigation, weather forecasting, and scientific research.

Questions:

Q1. (1 Mark) What are artificial satellites?
Answer: Man-made objects that orbit Earth. hecu111

Q2. (1 Mark) Mention one use of artificial satellites.
Answer: Communication / Weather forecasting / Navigation. hecu111

Q3. (2 Marks) How do satellites help humans in daily life?
Answer:
Satellites help in sending TV and phone signals, predicting weather, guiding navigation systems, and observing Earth from space.

✅ Long Answer Questions (5 Questions)

(5 Marks Each – High-Quality CBSE Answers)

1. Explain how the phases of the Moon occur.

Answer:
The Moon does not emit its own light. It shines because it reflects sunlight falling on its surface. The Moon revolves around Earth, and only the side facing the Sun is illuminated.

As the Moon moves in its orbit, the portion of the illuminated side visible from Earth changes. Sometimes we see the full illuminated part (Full Moon), sometimes only a small part (Crescent), and sometimes none (New Moon).

Thus, the changing shapes of the bright portion of the Moon seen from Earth are called the phases of the Moon. The Moon itself does not change shape; only the visible illuminated part changes. hecu111

2. Differentiate between waxing and waning phases of the Moon with examples.

Answer:
The Moon goes through two main phases:

Waxing Phase

• The bright portion of the Moon increases day by day.
• It occurs from New Moon to Full Moon.
• In India, it is called Shukla Paksha.

Waning Phase

• The bright portion of the Moon decreases day by day.
• It occurs from Full Moon to New Moon.
• In India, it is called Krishna Paksha.

Example: After Amavasya, the Moon waxes to become Full Moon. After Purnima, it wanes back to New Moon. hecu111

3. Describe how natural cycles of the Sun and Moon led to the development of calendars.

Answer:
Humans observed regular cycles in nature to measure time:

• Day: Based on Earth’s rotation, causing sunrise and sunset.
• Month: Based on the Moon’s phases cycle, which takes about 29.5 days.
• Year: Based on Earth’s revolution around the Sun, taking about 365 days and causing seasons.

These natural periodic events formed the basis of calendars. Ancient people created lunar calendars using Moon phases, while solar calendars were developed to stay aligned with seasons, important for agriculture. hecu111

4. Why are leap years necessary in the Gregorian calendar? Explain clearly.

Answer:
Earth takes about 365¼ days to complete one revolution around the Sun. A normal calendar year has only 365 days.

The extra ¼ day each year adds up to:
¼ + ¼ + ¼ + ¼ = 1 full day in four years.

To adjust this, one extra day is added every four years in February, making it 29 days. Such a year is called a leap year.

Leap years keep the calendar correctly aligned with seasons and prevent festivals and months from shifting over time. hecu111

5. What are artificial satellites? Mention their importance and uses.

Answer:
Artificial satellites are man-made objects launched into space that orbit Earth. They appear as moving points of light in the night sky.

Importance and Uses:

• Communication: TV, radio, telephone, internet signals
• Navigation: GPS and location tracking
• Weather forecasting: Predicting storms and rainfall
• Disaster management: Monitoring floods, cyclones, earthquakes
• Scientific research: Studying space and celestial bodies

India’s ISRO has launched many satellites such as Cartosat and AstroSat for these purposes.