✅ True or False (10 Questions)

(CBSE Class 8 Standard | Good Quality)

1. Science begins with curiosity and asking questions about the world.
   True hecu101

2. The questions on the first page of each chapter are meant for exams.
   False
   (They are meant to spark curiosity, not for exams.) hecu101

3. Investigation in science means only reading facts from books.
   False
   (It involves observing, experimenting and finding new facts.) hecu101

4. Scientific investigation requires careful observation and focused questioning.
   True hecu101

5. A kitchen can also be a place to do simple scientific experiments.
   True hecu101

6. While doing an experiment, it is better to change many things at the same time.
   False
   (Only one factor should be changed at a time.) hecu101

7. The puffing of a puri can be studied using scientific investigation.
   True hecu101

8. Measuring time taken for a puri to puff up is an example of observation.
   True hecu101

9. Scientific ideas never change once discovered.
   False
   (Science evolves with new questions and discoveries.) hecu101

10. Science works best when we balance careful observation with creative thinking.
    True

✅ Fill in the Blanks (10 Questions)

(CBSE Class 8 Standard | Good Quality)

1. Science begins with __________ and wonder about the world.
   Answer: curiosity hecu101

2. Asking “Why?” and “How?” are examples of scientific __________.
   Answer: questions hecu101

3. Scientific investigation requires careful __________ of things around us.
   Answer: observation hecu101

4. An experiment should change only one __________ at a time.
   Answer: variable hecu101

5. Science is not only done in laboratories but also in the __________.
   Answer: kitchen hecu101

6. The puffing of a puri can be studied through scientific __________.
   Answer: investigation hecu101

7. Recording results carefully is an important part of an __________.
   Answer: experiment hecu101

8. Science grows by asking new questions and making new __________.
   Answer: discoveries hecu101

9. Measurement helps in making observations more __________.
   Answer: accurate hecu101

10. Scientific thinking involves both logic and __________.
    Answer: creativity

✅ Multiple Choice Questions (15 MCQs)

(CBSE Class 8 Standard | Good Quality)

1. Science begins with:

A. Memorising facts
B. Curiosity and questions
C. Guessing answers
D. Copying experiments
✅ Answer: B hecu101

2. Scientific investigation mainly involves:

A. Only reading books
B. Observation and experimentation
C. Writing long notes
D. Ignoring results
✅ Answer: B hecu101

3. Which of the following is a scientific question?

A. What is my favourite colour?
B. Why does a puri puff up when heated?
C. Who is the best singer?
D. Which movie is fun?
✅ Answer: B hecu101

4. Changing only one factor at a time in an experiment is important to:

A. Make it confusing
B. Identify the cause of change
C. Waste time
D. Avoid results
✅ Answer: B hecu101

5. The things that can change in an experiment are called:

A. Conclusions
B. Variables
C. Observations
D. Discoveries
✅ Answer: B hecu101

6. Measuring time taken for a puri to puff is an example of:

A. Guessing
B. Observation with measurement
C. Opinion
D. Magic
✅ Answer: B hecu101

7. Science can be explored in:

A. Laboratories only
B. Classrooms only
C. Nature and daily life
D. Storybooks only
✅ Answer: C hecu101

8. The purpose of scientific investigation is to:

A. Prove assumptions always correct
B. Find answers through evidence
C. Avoid questions
D. Copy others
✅ Answer: B hecu101

9. Scientific ideas:

A. Never change
B. Change with new discoveries
C. Are always wrong
D. Are only for scientists
✅ Answer: B hecu101

10. The puffing of a puri is related to:

A. Science in daily life
B. Space travel
C. Music
D. Painting
✅ Answer: A hecu101

11. A good observation should be:

A. Careless
B. Accurate and detailed
C. Based on rumours
D. Ignored
✅ Answer: B hecu101

12. Science involves a balance of:

A. Luck and guessing
B. Observation and creativity
C. Silence and fear
D. Books and boredom
✅ Answer: B hecu101

13. The first step in investigation is:

A. Writing conclusion
B. Asking questions
C. Ignoring problem
D. Throwing materials
✅ Answer: B hecu101

14. Experiments help us to:

A. Test ideas
B. Avoid learning
C. Make guesses only
D. Copy results
✅ Answer: A hecu101

15. Science is best described as:

A. A set of fixed facts
B. A way of exploring the world
C. Only school subject
D. Only laboratory work
✅ Answer: B

✅ 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): Science begins with curiosity.
Reason (R): Curiosity leads us to ask questions about the world.
✅ Answer: A hecu101

2.

Assertion (A): Scientific investigation involves observation.
Reason (R): Observation helps in collecting evidence.
✅ Answer: A hecu101

3.

Assertion (A): Experiments should change only one variable at a time.
Reason (R): It helps identify the cause of the observed effect.
✅ Answer: A hecu101

4.

Assertion (A): Science is not limited to laboratories.
Reason (R): Science can be explored in daily life activities like cooking.
✅ Answer: A hecu101

5.

Assertion (A): The puffing of a puri can be studied scientifically.
Reason (R): It involves heat, air expansion and observation.
✅ Answer: A hecu101

6.

Assertion (A): Scientific ideas can change over time.
Reason (R): New discoveries and evidence improve scientific understanding.
✅ Answer: A hecu101

7.

Assertion (A): Measurement makes observation more accurate.
Reason (R): Quantitative data reduces guesswork.
✅ Answer: A hecu101

8.

Assertion (A): Asking questions is the first step in investigation.
Reason (R): Questions guide experiments and observations.
✅ Answer: A hecu101

9.

Assertion (A): Scientific thinking requires creativity.
Reason (R): Creativity helps in designing new experiments and ideas.
✅ Answer: A hecu101

10.

Assertion (A): Science is a way of exploring the world.
Reason (R): It helps us understand nature through evidence and reasoning.
✅ Answer: A

✅ Very Short Answer Questions (10 Questions)

(2 Marks Each | CBSE Class 8 Standard | Good Quality)

1. What is science?

Answer:
Science is a way of exploring and understanding the world around us through observation, experimentation, and evidence. hecu101

2. What is the first step in scientific investigation?

Answer:
The first step is curiosity and asking questions about natural phenomena. hecu101

3. What is observation?

Answer:
Observation is the careful watching and noting of events or objects using our senses and tools. hecu101

4. What is an experiment?

Answer:
An experiment is a planned scientific test done to find answers by changing one factor and observing results. hecu101

5. Why should only one variable be changed in an experiment?

Answer:
Changing only one variable helps us understand which factor causes the observed effect. hecu101

6. Give one example of science in daily life.

Answer:
The puffing of a puri while frying is an example of science in daily life. hecu101

7. What are variables in an experiment?

Answer:
Variables are the factors or conditions that can change during an experiment. hecu101

8. Why is measurement important in science?

Answer:
Measurement makes observations accurate and helps in drawing correct conclusions. hecu101

9. Does science always remain the same?

Answer:
No, scientific ideas change with new evidence and discoveries. hecu101

10. How does creativity help in science?

Answer:
Creativity helps scientists design experiments, think of new ideas, and solve problems in innovative ways.

✅ Short Answer Questions (10 Questions)

(3 Marks Each | CBSE Class 8 Standard | Good Quality)

1. Explain why curiosity is important in science.

Answer:
Curiosity is important in science because it makes us ask questions about the world around us. These questions lead to observations, experiments, and new discoveries. Without curiosity, scientific progress is not possible. hecu101

2. What is scientific investigation?

Answer:
Scientific investigation is a systematic process of exploring a question through observation, experimentation, measurement, and reasoning. It helps us find answers based on evidence rather than guesses. hecu101

3. Why should experiments be planned carefully?

Answer:
Experiments should be planned carefully to ensure correct results. Only one variable should be changed at a time, observations should be accurate, and results should be recorded properly for valid conclusions. hecu101

4. Explain the importance of observation in science.

Answer:
Observation is important because it provides evidence about natural events. Careful observation helps scientists identify patterns, ask meaningful questions, and design experiments for investigation. hecu101

5. What are variables? Give one example.

Answer:
Variables are factors that can change in an experiment. Example: While studying puri puffing, oil temperature is a variable that affects the result. hecu101

6. How can a kitchen activity be an example of science?

Answer:
Many kitchen activities involve science, such as puffing of puri, boiling water, or fermentation of dough. These processes can be studied through observation and experimentation. hecu101

7. Why is measurement important in scientific investigation?

Answer:
Measurement provides accurate and quantitative information. It reduces guesswork and helps in comparing results, making conclusions more reliable. hecu101

8. Explain why scientific ideas change over time.

Answer:
Scientific ideas change because new discoveries and evidence improve our understanding. Science is not fixed; it evolves as we learn more through investigation. hecu101

9. What is the role of creativity in science?

Answer:
Creativity helps scientists think of new questions, design experiments, and develop innovative solutions. Science needs both logical reasoning and creative thinking. hecu101

10. Describe the puffing of puri as a scientific investigation.

Answer:
The puffing of puri can be studied scientifically by observing changes when puri is heated. Experiments can be done by changing oil temperature, thickness of dough, and measuring puffing time to understand the process.

✅ Case-Based Questions (4 Cases)

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

Case 1: Curiosity Leads to Science

A student observes that the sky changes colour during sunset. He becomes curious and asks why this happens. His teacher explains that curiosity is the starting point of science.

Questions:

Q1. (1 Mark) What is the first step of scientific investigation?
Answer: Curiosity and asking questions hecu101

Q2. (1 Mark) What type of question is “Why does the sky change colour?”
Answer: Scientific question hecu101

Q3. (2 Marks) Why is curiosity important for scientific progress?
Answer:
Curiosity leads to questioning, observation, and experiments, which help in making new discoveries and improving scientific knowledge. hecu101

Case 2: Experiment in the Kitchen

Meera notices that puris puff up while frying. She decides to investigate by changing oil temperature and observing results.

Questions:

Q1. (1 Mark) Puffing of puri is an example of science in:
Answer: Daily life hecu101

Q2. (1 Mark) What is the factor Meera changes in her experiment?
Answer: Oil temperature (variable) hecu101

Q3. (2 Marks) Why should only one variable be changed at a time?
Answer:
Changing one variable helps identify the exact cause of the observed effect, making results reliable. hecu101

Case 3: Importance of Measurement

A student records the time taken for puris to puff up at different temperatures. This helps in comparing results.

Questions:

Q1. (1 Mark) Recording time is an example of:
Answer: Measurement hecu101

Q2. (1 Mark) Why is measurement important in science?
Answer: It makes observations accurate hecu101

Q3. (2 Marks) How does measurement improve scientific investigation?
Answer:
Measurement provides quantitative data, reduces guesswork, and helps in drawing correct conclusions. hecu101

Case 4: Science Changes with Discoveries

Earlier people believed Earth was flat, but later evidence proved it is spherical. This shows science evolves.

Questions:

Q1. (1 Mark) Do scientific ideas remain fixed forever?
Answer: No hecu101

Q2. (1 Mark) What causes changes in scientific ideas?
Answer: New evidence and discoveries hecu101

Q3. (2 Marks) Why is science called an evolving subject?
Answer:
Because scientific knowledge improves over time with new experiments, observations, and discoveries.

✅ Long Answer Questions (5 Questions)

(5 Marks Each | CBSE Class 8 Standard | High Quality Answers)

1. What is science? Explain how curiosity leads to scientific investigation.

Answer:
Science is a systematic way of exploring and understanding the world around us through observation, experimentation, and evidence.

Curiosity is the starting point of science. When we observe something unusual, we ask questions like “Why?” and “How?”. These questions lead to investigation. Scientists then perform experiments, record observations, and draw conclusions based on evidence.

Thus, curiosity leads to discoveries and growth of scientific knowledge. hecu101

2. Explain the steps involved in a scientific investigation with an example.

Answer:
Scientific investigation involves the following steps:

1. Observation: Noticing something in nature.
2. Asking Questions: For example, “Why does a puri puff up?”
3. Planning an Experiment: Testing the idea by changing one factor.
4. Recording Results: Measuring and noting observations carefully.
5. Conclusion: Finding the reason based on evidence.

Example: Studying puri puffing by changing oil temperature and observing puffing time.

Thus, investigation is a systematic method of learning. hecu101

3. Why is it important to change only one variable at a time in an experiment?

Answer:
Changing only one variable at a time is important because:

• It helps identify the exact cause of the effect.
• If many factors change together, results become confusing.
• Scientific conclusions become reliable only when experiments are controlled.

Example: While studying puri puffing, only oil temperature should be changed, not thickness and frying time together.

Thus, controlling variables ensures correct results. hecu101

4. Explain the importance of observation and measurement in science.

Answer:
Observation is the foundation of science because it provides evidence about natural events.

Measurement makes observations accurate and quantitative. It reduces guesswork and helps compare results.

For example, measuring the time taken for a puri to puff gives more accurate information than just saying it puffed quickly.

Thus, observation and measurement help in drawing correct scientific conclusions. hecu101

5. Why is science considered an evolving subject? Explain with an example.

Answer:
Science is considered an evolving subject because scientific knowledge changes with new discoveries and evidence.

Old ideas may be modified or replaced when better explanations are found.

Example: Earlier people believed Earth was flat, but later scientific investigations proved it is spherical.

Thus, science grows continuously through curiosity, experiments, and new understanding.