CBSE Class 8 Important Questions for All Subjects

Author at PW
March 10, 2025

CBSE Class 8 Important Questions for All Subjects:- For Class 8 students, it’s essential to start by thoroughly completing the NCERT textbooks. These books are designed to give you a strong foundation, and most exam questions are directly based on the concepts covered in them. Once you’ve worked through your NCERT, the next important step is to go over class 8 important questions. These questions are handpicked because many of them tend to show up in exams year after year.  

Class 8 important questions can make all the difference in helping you focus on what truly matters. These carefully selected class 8 questions will guide you through the most important topics in each subject, ensuring you’re ready for anything that comes your way. Whether it's class 8 important questions in Mathematics, Science, English, or Social Science, these resources help you get a solid grip on the key concepts. Check out the below article for CBSE Class 8 Important Questions for All Subjects.

Check out: PW Class 8th Books

CBSE Class 8 Important Questions for Science

Question 1. What is the name of the undesirable plants that grow among the crops?

Answer: Weeds

Question 2. Name one weed.

Answer: Wild oat

Question 3. Name the methods applied for weeding.

Answer: 

  • Manual method

  • Chemical method

  • Biological method

Question 4. Name the chemicals that are used to remove weeds.

Answer: Weedicides

Question 5. Name a tool which is used for removing weeds and for loosening soil.

Answer: Hoe

Question 6. What is the process of loosening and turning of the soil called?

Answer: Tilling or ploughing

Question 7. What are the substances which are added to the soil in the form of nutrients called?

Answer: Manure and fertilisers

Question 8. What is the process of supplying water to crops at different intervals is called?

Answer: Irrigation

Question 9. What are the sources of irrigation?

Answer: Wells, tubewells, ponds, lakes, etc.

Question 10. What is fermentation?

Answer: Fermentation is the process of conversion of food into alcohol.

Question 11. Define refrigeration.

Answer: The storing of food products at the temperature of 0°C to 5°C is known as refrigeration.

Question 12. What is vaccine?

Answer: A substance which is used in the production of immunity against various diseases in the living body is termed as vaccine.

Question 13. Name any two human diseases caused by viruses.

Answer: Measles & Polio

Question 14. Name any three common plant diseases.

Answer: Rust of wheat, citrus canker and wilt

Question 15. Name a microorganism which helps in nitrogen fixation.

Answer: Rhizobium

Check out: Class 8th Combo Set of 5 Books

CBSE Class 8 Important Questions for Maths

Question 1. In the given figure, ABCD is a parallelogram. Find x.

Solution: AB = DC [Opposite sides of a parallelogram]

3x + 5 = 5x – 1

⇒ 3x – 5x = -1 – 5

⇒ -2x = -6

⇒ x = 3

Question 2. In the given figure find x + y + z.

Solution: We know that the sum of all the exterior angles of a polygon = 360°

x + y + z = 360°

Question 3. Form a linear equation from the given statement: ‘When 5 is added to twice a number, it gives 11.’
Solution: As per the given statement we have
2x + 5 = 11 which is the required linear equation.

Question 4. Verify that x = 2 is the solution of the equation 4.4x – 3.8 = 5.
Solution: We have 4.4x – 3.8 = 5
Putting x = 2, we have
4.4 × 2 – 3.8 = 5
⇒ 8.8 – 3.8 = 5
⇒ 5 = 5
L.H.S. = R.H.S.
Hence verified.

Question 5. The angles of a triangle are in the ratio 2 : 3 : 4. Find the angles of the triangle.
Solution: Let the angles of a given triangle be 2x°, 3x° and 4x°.

2x + 3x + 4x = 180 (∵ Sum of the angles of a triangle is 180°)

⇒ 9x = 180

⇒ x = 20 (Transposing 9 to RHS)

Angles of the given triangles are

2 × 20 = 40°

3 × 20 = 60°

4 × 20 = 80°

Question 6. The sum of two numbers is 11 and their difference is 5. Find the numbers.

Solution: Let one of the two numbers be x.

Other number = 11 – x.

As per the conditions, we have

x – (11 – x) = 5

⇒ x – 11 + x = 5 (Solving the bracket)

⇒ 2x – 11 = 5

⇒ 2x = 5 + 11 (Transposing 11 to RHS)

⇒ 2x = 16

⇒ x = 8

Hence the required numbers are 8 and 11 – 8 = 3.

Question 7. If the sum of two consecutive numbers is 11, find the numbers.

Solution: Let the two consecutive numbers be x and x + 1.

As per the conditions, we have

x + x + 1 = 11

⇒ 2x + 1 = 11

⇒ 2x = 11 – 1 (Transposing 1 to RHS)

⇒ 2x = 10

x = 5

Hence, the required numbers are 5 and 5 + 1 = 6.

Question 8. The angles of a quadrilateral are in the ratio of 2 : 3 : 5 : 8. Find the measure of each angle.

Solution: Sum of all interior angles of a quadrilateral = 360°

Let the angles of the quadrilateral be 2x°, 3x°, 5x° and 8x°.

2x + 3x + 5x + 8x = 360°

⇒ 18x = 360°

⇒ x = 20°

Hence the angles are

2 × 20 = 40°,

3 × 20 = 60°,

5 × 20 = 100°

and 8 × 20 = 160°.

Question 9. Construct a quadrilateral PQRS, given that QR = 4.5 cm, PS = 5.5 cm, RS = 5 cm and the diagonal PR = 5.5 cm and diagonal SQ = 7 cm.
Solution: Construction:
Step I: Draw QR = 4.5 cm.
Step II: Draw an arc with centre R and radius 5 cm.
Step III: Draw another arc with centre Q and radius 7 cm to meet the previous arc at S.
Step IV: Join RS and QS.
Step V: Draw two arcs with centre S and R and radius 5.5 cm each to meet each other at P.
Step VI: Join RP, SP and PQ.
Thus PQRS is the required quadrilateral.

Question 10. Construct a square whose side is 5 cm.
Solution: Construction:
Step I: Draw AB = 5 cm.
Step II: Draw an angle of 90° at B and cut BC = 5 cm.
Step III: Draw two arcs with centre A and C and same radii of 5 cm which meet each other at D.
Step IV: Join AD and CD.
Thus, ABCD is the required square.

Question 11. Construct a rhombus ABCD in which AB = 5.8 cm and AC = 7.5 cm.
Solution: Construction:
Step I: Draw AB = 5.8 cm.
Step II: Draw an arc with centre B and radius 5.8 cm.
Step III: Draw another arc with centre A and radius 7.5 cm to meet the previous arc at C.
Step IV: Draw two arcs with centres A and C and of the same radius 5.8 cm to meet each other at D.
Step V: Join BC, AC, CD and AD.
Thus ABCD is the required rhombus.

Question 12. Construct a rhombus whose diagonals are 6 cm and 8 cm.
Solution: Construction:
Step I: Draw SQ = 8 cm.
Step II: Draw a right bisector of SQ at O.
Step III: Draw two arcs with centre O and radius 3 cm each to cut the right bisector at P and R.
Step TV: Join PQ, QR, RS and SP.
Thus PQRS is the required rhombus.

Question 13. Construct a rectangle whose diagonal is 5 cm and the angle between the diagonal is 50°.
Solution: Construction:
Step I: Draw AC = 5 cm.
Step II: Draw the right bisector of AC at O.
Step III: Draw an angle of 50° at O and product both sides.
Step IV: Draw two arcs with centre O and of the same radius 2.5 cm to cut at B and D.
Step V: Join AB, BC, CD and DA.
Thus, ABCD is the required rectangle.

Question 14. Write the following numbers in generalised form.
(a) ab
(b) 85
(c) 132
(d) 1000
Solution:
(a) ab = 10 × a + 1 × b = 10a + b
(b) 85 = 10 × 8 + 1 × 5 = 10 × 8 + 5
(c) 132 = 100 × 1 + 10 × 3 + 1 × 2 = 100 × 1 + 10 × 3 + 2
(d) 1000 = 1000 × 1

Question 15. Write the following in usual form.
(a) 3 × 100 + 0 × 10 + 6
(b) 5 × 1000 + 3 × 100 + 2 × 10 + 1
Solution:
(a) 3 × 100 + 0 × 10 + 6 = 300 + 0 + 6 = 306
(b) 5 × 1000 + 3 × 100 + 2 × 10 + 1 = 5000 + 300 + 20 + 1 = 5321

Check out: PW School Books

CBSE Class 8 Important Questions for Social Science

Question 1: Define the word ‘history’.

Solution: History is ‘a record of all known past events’.

Question 2: What are the events that are usually recorded in history books?

Solution: The events that are usually recorded are wars, crowning of kings and events related to kingdoms and the lives of rulers.

Question 3: Mention a few other events, which if recorded, will make history more interesting to everyone.

Solution: Historians could write about the cultural changes in society, about how people travelled and exchanged news in the olden days and about the livelihood of people in the past.

Question 4 Who created the first map of India?

Solution: Major James Rennel an English geographer, historian and pioneer of oceanography prepared the first Map of India. He was directed by Major-General Sir Robert Clive to prepare the map.

Question 5: What do we mean by ‘time-span’ in connection with historical events?

Solution: When a specific date cannot be fixed for an event in the past and only an approximate period can be fixed this period of time is called the time-span. When we talk about changes that took place in certain social practices specific dates cannot be fixed only a time-span can be mentioned, like ‘ people in India gave up the practice of sati during the late 19th century’.

Question 6: Write a brief note on wind power?

Solution : 

  • Wind power is the fastest-growing energy source in the world. A wind turbine works the opposite of a fan. Instead of using electricity to make wind, a turbine uses wind to make electricity

  • The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity. The electricity is sent through transmission and distribution lines to a substation, then on to homes, business houses and schools.

  • Wind turbines do not have any adverse effect on the environmental. That’s why wind power is gaining popularity. It is also becoming economically competitive with more conventional power sources – a fact that’s greatly improving its prospects as a viable energy source.

Question 7: What are abiotic resources?

Solution: Abiotic Natural Resource :

  • Abiotic resources comprise of non-living things like land, water, air and minerals such as gold, iron, copper and silver.

  • Abiotic resources are not renewable, as they can be exhausted by excessive use and their rate of formation is very slow.

  • The usefulness of the abiotic resources depends upon their accessibility and their value.

  • Their total reserve cannot be increased by human efforts.

  • These resources are in great demand for the development of industries.

Question 8: Write a brief note on Renewable resources?

Solution : Renewable Resources :

  • Renewable resources are resources which can be replaced or reproduced easily. Sunlight, air and wind are resources that are continuously available and their quantity is not affected by human consumption.

  • Many renewable resources can be depleted by human use, but are replaced and the balance is maintained. For example agricultural crops, take a short time for renewal; others, like water, take a comparatively longer time, while still others, like forests, take even longer.

Question 9: When can people make the best use of nature?

Solution : People can make the best use of nature to create more resources when they have :

  • Knowledge

  • Skill

  • Technology

Question 10: What can we do to conserve resources?

Solution : To conserve natural resources we have to :

  • Ensure that our natural resources are preserved.

  • Ensure that we do not destroy our ecosystem.

  • Renew resources where ever and whenever possible.

Question 11: What is universal adult franchise?

Solution: Universal adult franchise is every adult citizen having a right to vote irrespective of sex, caste, creed, education and financial status.

Question 12: What do you mean by the legislature, the executive and the judiciary?

Solution:

  • The legislature refers to our elected representatives.

  • The executive is a smaller group of people who are responsible for implementing laws and running the government.

  • The judiciary refers to the system of courts in this country.

Question 13: What are the key components of fundamental rights?

Solution: The key components of Fundamental rights are:-

  • Right to Equality

  • Right to Freedom

  • Right against Exploitation

  • Right to Freedom of Religion

  • Cultural and Educational Rights

  • Right to Constitutional Remedies

Question 14: What is secularism?

Solution: Secularism is the right of the citizens to practice any religion. A secular state is one in which the state does not officially promote any one religion as the state religion.

Question 15: What are the factors the drafting committee had to take into consideration while drafting the constitution?

Solution: The committee had to keep in mind that India was a land of many communities, languages and many religions. India was a land of diverse cultures and the Princely states in India had to be considered. The partition of the country into India and Pakistan was about to happen and the drafting committee had to bear this in mind. Finally the biggest consideration was the socio-economic condition of a majority of Indians which was in a bad state.

Read More: CBSE Class 8 Subject-Wise Important Topics

CBSE Class 8 Important Questions for English

Question 1. Describe the condition of the roll-top box. From where the author found the roll-top box? 

Answer: The roll-top box was made up of oak. It was in very bad condition. It brings scorch marks all down one side & one leg is clumsily mended. He found roll-top box from a junk shop in Bridport

Question 2. Why did the author buy roll top box even though it was in bad condition? 

Answer: The author bought roll top box in bad condition because it cost little money and he could easily restore it by working on it.

Question 3. What did the author find in the secret-drawer?

Answer: He found a tin-box cello - taped to the top of that was a piece of lined notepaper in the secret drawer.

Question 4. What was written on the tin box?

Answer: 'Jim's last letter, received January 25, 1915. was written on the tin box.

Question 5. What is Tsunami? What happened on 26 Dec, 2004?

Answer: Tsunami is a very large and powerful wave caused by earthquakes under the sea. On 26 December 2004, a tsunami hit Thailand & parts of India such as Andaman & Nicobar Islands, and the Tamil Nadu Coast.

Question 6. Who first felt an earthquake at Andaman & Nicobar?

Answer: Ignesious was the manager of a cooperative society in Katchall. His wife felt an earthquake at 6 a.m. in the morning. Ignesious carefully took his television set off its table and put it down on the ground so that it would not fall and break.

Question 7. What happened with Meghna?

Answer: Meghna was a 13-years old girl who swept away along with her parents and 77 other people. She spent two days floating in the sea, holding on to a wooden door 11 times. She saw relief helicopter overhead,. but they didn't see her. At last, she was found walking on the seashore in a daze.

Question 8. What was the young cricket accustomed to do?

Answer: The young cricket accustomed to sing all day long and enjoyed his good times.

Question 9. When was cricket happier?

Answer: The cricket was happier through the warm, sunny months of gay summer and spring.

Question 10.How Macavity does outwit the world's top investigation agencies?

Answer: Whenever investigation agencies reach the spot of crime, Macavity is not present there. He also didn't leave any clue of him. These agencies were not able to find any sign of Macavity. Therefore, he outwitted the world's top investigation agencies.

Question 11. What is the most remarkable thing about Macavity?

Answer: Macavity, known as the Mystery cat has defied all laws. He even defies the law of gravity. He possesses supernatural powers which allow him to levitate up in the air. He is so confident in his manner that

Whenever the crime is discovered, Macavity disappears without leaving a single trace.

Question 12. What geographic lessons did the poet in the jet learn when the jet just took off? 

Answer: The city that humans have developed has not been well planned, it grew as per necessity.

Question 12. What geographic lessons did the poet in the jet learn when the jet reached ten thousand feet? 

Answer: From a height of ten thousand feet above the ground, the earth's cities were found located on the banks of rivers and a little above the river level, in valleys.

Question 13. What was once most necessary for the emergence of a city in the past?

Answer: The easy availability of water for drinking to irrigation was the prime reason why civilization flocked around rivers.

Question 14. What was difficult to understand about the earth when the jet was six miles high?

Answer: It was difficult to understand why human hate each other, build borders, walls and create fences.

Question 15. What is the poet trying to bring out about human being the earth and learning? 

Answer: The poet is trying to bring out the fact that human beings have achieved a lot of knowledge about the earth

and beyond. We have learnt much about the earth, its shape, the emergence of cities and nations, but we have failed to learn how to love each other and live peacefully on this wonderful planet.

Preparation Tips of CBSE Class 8 

1. Complete Your NCERT Textbooks First

Before anything else, make sure you thoroughly study your NCERT textbooks for each subject. These books provide the foundation for most of your exam questions. Stick to the class 8 important questions from the exercises at the end of each chapter to get a clear understanding.

2. Understand the Chapter Concepts Well

Instead of memorising answers, try to understand the core concepts of each chapter. This will help you answer class 8 questions confidently. For example, in Science, understand the process of photosynthesis or in Maths, understand the methods to solve equations.

3. Practice Important Questions Regularly

Focus on class 8 important questions that are likely to appear in exams. These are often repeated or focus on key topics. Make sure you practice them daily, especially important questions for class 8 maths like mensuration, linear equations, and geometry.

4. Solve Previous Year Papers

Go through the question for class 8 from previous years. Solving these papers will help you get used to the exam pattern and improve your time management. It’s a great way to identify what type of questions are asked most frequently.

5. Focus on Diagrams and Charts

In subjects like Science and Maths, diagrams play a huge role. Practice drawing clear and labelled diagrams like the structure of a cell in Science or graphs in Maths. These questions appear often in exams, and practising them ensures you don’t miss any marks.

6. Revise Key Formulas and Concepts

In Maths, make sure you memorise important formulas like those for area, perimeter, and volume. Similarly, revise key concepts in other subjects such as the laws of motion in Science. Keeping these formulas handy will save time during the exam.

7. Take Short Breaks and Stay Consistent

Don’t overburden yourself with long study sessions. Take small breaks between your study hours to stay fresh. This will help you retain more information in the long run. Consistency is key in preparing for class 8 question answers effectively.

8. Work on Writing and Presentation Skills

In subjects like English and Social Science, presenting your answers clearly and neatly matters. Practice writing your answers in a concise and structured way. Make sure your handwriting is legible and the information is organised logically.

9. Use Online Resources for Practice

If you’re struggling with some topics, consider using online resources. Websites offering class 8 all subject question answer sets or videos on important questions for class 8 can provide additional explanations and practice.

10. Revision

Keep revising regularly. After completing each topic, assess yourself by taking small quizzes or tests. This will help you check how much you’ve learned and identify areas that need more practice. Make sure you revise class 8 important question sets a few days before the exam to boost your memory.

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CBSE Class 8 Important Questions FAQs

1. What are the core subjects in Class 8?

Maths, Science, English, Social Science, and Hindi are the core subjects.

2. How can I improve in Class 8 Maths?

Practice algebra, fractions, and geometry. Solve class 8 important questions regularly.

3. What should I focus on in Science?

Focus on concepts like photosynthesis, acids and bases, and practice drawing diagrams like the digestive system.

4. Why should I solve previous year papers?

Solving previous year question papers helps understand the exam pattern and time management.

5. How can I prepare for Social Science?

Focus on key topics like Indian History, Geography, and practice important questions.

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