Hard

Exploring the Investigative World of Science — Hard

15 questions 18 min PYQ-grade reasoning

Q1. Consider the following statements about the puri-puffing investigation in the chapter. I. While doing experiments, it is better to change only one thing at a time. II. To see the effect of oil temperature, the dough thickness should also be changed. III. The way the dough is dropped into the oil is something we can control. Which are correct?
- A. I and II only
- B. II and III only
- C. I and III only
- D. All three
Q2. Assertion (A): To test the effect of oil temperature on puri puffing, we should use dough circles of the same thickness and drop them in the same way. Reason (R): In a scientific investigation, we change only one variable at a time and keep the other conditions the same.
- 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, R is false.
- D. A is false, R is true.
Q3. Consider three statements about what we 'observe or measure' in the puri experiment. I. Whether the puri puffs up has a yes/no answer. II. The time taken to puff up can be measured in seconds. III. Whether a thick layer of dough still gives a thin side is something we cannot check. Which are correct as per the chapter?
- A. I and II only
- B. II and III only
- C. I and III only
- D. All three
Q4. A Class 8 student lists the following as 'things we can control' in the puri experiment: I. The thickness and size of the rolled dough II. The kind of flour used (atta, maida etc.) III. Whether the puri puffs up (yes/no) Which are correctly classified as controllable variables, per the chapter?
- A. I and II only
- B. II and III only
- C. I and III only
- D. All three
Q5. Assertion (A): In Class 8, each student is not just a learner but also an investigator — a young scientist exploring real-world puzzles. Reason (R): The Class 8 textbook expects students to mainly memorise facts that scientists have already discovered.
- 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, R is false.
- D. A is false, R is true.
Q6. Read the three statements about how Class 8 sees the journey of science. I. Wonder (Grade 6) and evolution of ideas (Grade 7) come together in Grade 8. II. In the investigative world, both wonder and evolution form the heart of how science works. III. Grade 8 leaves wonder behind and uses only fact-finding. Which are correct?
- A. I and II only
- B. II and III only
- C. I and III only
- D. All three
Q7. Aditi is doing the puri experiment with a senior at home. According to the chapter, while doing the experiment she should also
- A. Avoid writing anything until the puri is fully cooked
- B. Keep notes of everything she sees and senses — whether the oil splattered, smelled or smoked
- C. Note only the final result (puffed or not)
- D. Skip the senses (smell, sight) and trust only the timer
Q8. After one round of puri experiments, the chapter says we may think of new questions such as
- A. Whether the syllabus will end in time
- B. Whether the teacher liked the puri
- C. Whether puris puff better when made fresh or from stored dough, or what happens if a hole is pricked before frying
- D. Whether the puri is best sold in the market
Q9. Read three statements about the puri example in the chapter. I. Even this everyday observation of a puri puffing is not really completely understood by scientists today. II. Because scientists understand the puri completely, students need not investigate it. III. Even a simple kitchen phenomenon can be the subject of systematic investigation. Which are correct as per the chapter?
- A. I and II only
- B. II and III only
- C. I and III only
- D. All three
Q10. A teacher uses the puri-puffing question to start the year. She first asks students what they already notice in their kitchens. This best matches the pedagogical principle that
- A. Children learn nothing from the kitchen
- B. Teachers should ignore home experiences in science
- C. New scientific learning is built on the learner's prior, everyday observations (constructivism)
- D. Science must always start from textbook definitions
Q11. A Class 8 teacher wants to assess whether students have understood the 'one variable at a time' idea. The best assessment task, in the spirit of the chapter, is to ask students to
- A. Recite the page-2 paragraph word-for-word
- B. Translate the chapter into Hindi
- C. Plan a kitchen experiment, name what they will change, what they will keep the same, and what they will observe
- D. Draw the root-and-kite logo neatly
Q12. Consider these three statements about the kinds of puzzles Class 8 investigation will explore. I. The puzzles range from everyday life (like 'Why does dough rise?') to planet-scale ('Is the world getting warmer?'). II. Only everyday kitchen puzzles count as scientific. III. Investigation can connect small home observations to large Earth-scale questions. Which are correct?
- A. I and II only
- B. II and III only
- C. I and III only
- D. All three
Q13. Three statements about Earth and climate as previewed in the chapter: I. Earth's atmosphere shields us from harmful ultraviolet rays. II. Human activities can cause small changes in Earth's temperature, disrupting climate patterns. III. Climate change cannot be influenced by human activities at all. Which are correct?
- A. I and II only
- B. II and III only
- C. I and III only
- D. All three
Q14. Assertion (A): The same scientific principles of observing, measuring and experimenting can help us protect the delicate balance on which life depends. Reason (R): These middle-stage habits of science are useless once we face planet-scale challenges like climate change.
- 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, R is false.
- D. A is false, R is true.
Q15. Consider three statements about root, kite, and investigation in Class 8 Curiosity. I. Investigation in science works best when careful observation and creative thinking are balanced. II. The root stands for creative thinking only. III. The kite reminds us that curiosity must take flight to explore the unknown. Which are correct?
- A. I and II only
- B. II and III only
- C. I and III only
- D. All three

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