NCERT Class 9 Science MCQ | Chapter 1: Exploration: Entering the World of Secondary Science
1. What is the main emphasis of science at the secondary stage according to the chapter?
(A) Memorising scientific facts
(B) Deep exploration and understanding
(C) Performing experiments without asking questions
(D) Learning only mathematical equations
Answer: (B) Deep exploration and understanding
2. According to the chapter, science began with ______ and grew through careful experiments.
(A) memorisation
(B) calculation
(C) wonder
(D) prediction
Answer: (C) wonder
3. What does science help us understand about the natural world?
(A) Only what we know
(B) Only mathematical calculations
(C) What we know and how we know it
(D) Only experimental results
Answer: (C) What we know and how we know it
4. Which symbol in the textbook represents careful observation?
(A) Compass
(B) Magnifying glass
(C) Thermometer
(D) Balance
Answer: (B) Magnifying glass
5. What does the compass symbolise in the textbook?
(A) Measurement of distance
(B) Direction and purposeful exploration
(C) Mathematical calculation
(D) Experimental equipment
Answer: (B) Direction and purposeful exploration
6. Why does science use models?
(A) To make every detail of nature more complicated
(B) To avoid making observations
(C) To simplify complex real systems
(D) To replace experiments completely
Answer: (C) To simplify complex real systems
7. A scientific model focuses mainly on:
(A) Every possible detail
(B) The details most important for a given question
(C) Only visual features
(D) Only numerical values
Answer: (B) The details most important for a given question
8. How may a moving car be represented in a simple physics model?
(A) As a complete photograph
(B) As a single point
(C) As a collection of atoms
(D) As a detailed mechanical diagram
Answer: (B) As a single point
9. In a simple model of a falling object, which factor may be deliberately neglected?
(A) Gravity
(B) Object’s motion
(C) Air resistance
(D) Time
Answer: (C) Air resistance
10. According to the cricket-shot example, which factor is important when determining whether the ball will cross the boundary without hitting the ground?
(A) Colour of the ball
(B) Brand of the bat
(C) Mass of the ball
(D) Amount of grass on the field
Answer: (C) Mass of the ball
11. Which of the following is considered less important in a simple model of a cricket shot?
(A) Speed of the ball
(B) Direction of the ball
(C) Mass of the ball
(D) Colour of the ball
Answer: (D) Colour of the ball
12. Why may some details be ignored while building a scientific model?
(A) Because those details are always incorrect
(B) To keep the model simple enough to answer the question
(C) Because experiments cannot measure them
(D) To avoid using mathematics
Answer: (B) To keep the model simple enough to answer the question
13. What happens as scientific models become more complex?
(A) More details may be added for greater accuracy
(B) All observations are removed
(C) Measurements become unnecessary
(D) Scientific questions become impossible
Answer: (A) More details may be added for greater accuracy
14. Why does science use precise language?
(A) To make scientific ideas difficult
(B) To communicate ideas clearly and unambiguously
(C) To avoid using symbols
(D) To replace observations
Answer: (B) To communicate ideas clearly and unambiguously
15. Which of the following quantities is represented by the symbol ‘m’ in the chapter?
(A) Mass
(B) Motion
(C) Meter
(D) Momentum
Answer: (A) Mass
16. Which symbol is used for velocity in the chapter?
(A) F
(B) I
(C) v
(D) m
Answer: (C) v
17. Which symbol is used for electric current in the chapter?
(A) I
(B) F
(C) m
(D) v
Answer: (A) I
18. According to the chapter, mathematics in science is best described as:
(A) A hurdle that students must overcome
(B) A language for thinking clearly about the world
(C) A replacement for experiments
(D) A method used only for numerical answers
Answer: (B) A language for thinking clearly about the world
19. What should be done before using a mathematical relationship in science?
(A) Memorise every equation
(B) Understand the situation and identify relevant quantities
(C) Ignore the physical situation
(D) Calculate immediately
Answer: (B) Understand the situation and identify relevant quantities
20. What does an equation represent according to the chapter?
(A) Only a calculation
(B) A compact statement about how certain things are related
(C) A scientific guess
(D) A laboratory instrument
Answer: (B) A compact statement about how certain things are related
21. Who is mentioned in the chapter as a scientist who simplified the study of stars?
(A) Isaac Newton
(B) Meghnad Saha
(C) Albert Einstein
(D) Galileo Galilei
Answer: (B) Meghnad Saha
22. In studying stars, what did Meghnad Saha focus on according to the chapter?
(A) Every atom and every movement inside a star
(B) Temperature, pressure, and how atoms formed ions
(C) The shape and colour of telescopes
(D) The distance between every star
Answer: (B) Temperature, pressure, and how atoms formed ions
23. What does a scientific law usually describe?
(A) A personal opinion
(B) A regular pattern observed in nature
(C) An untested guess
(D) A laboratory mistake
Answer: (B) A regular pattern observed in nature
24. What does a scientific theory provide?
(A) An explanation of why observed patterns occur
(B) A list of unrelated observations
(C) A personal belief
(D) An exact prediction of every future event
Answer: (A) An explanation of why observed patterns occur
25. Which statement about a scientific theory is correct according to the chapter?
(A) It means an untested guess
(B) It can never change
(C) It is an explanation based on careful testing and critical examination
(D) It is based only on personal opinion
Answer: (C) It is an explanation based on careful testing and critical examination
26. What are principles described as in the chapter?
(A) Broad ideas that help us make sense of a situation
(B) Exact measurements
(C) Scientific instruments
(D) Unverified predictions
Answer: (A) Broad ideas that help us make sense of a situation
27. What is one important strength of science discussed in the chapter?
(A) It never changes
(B) It can make predictions
(C) It avoids measurements
(D) It depends on opinions
Answer: (B) It can make predictions
28. What should scientists do when predictions do not match observations?
(A) Ignore the observations
(B) Accept the prediction anyway
(C) Re-examine assumptions, models, or measurements
(D) Replace evidence with opinion
Answer: (C) Re-examine assumptions, models, or measurements
29. Why can weather forecasts sometimes become less certain further into the future?
(A) Weather never changes
(B) Weather depends on many changing factors and small differences can grow over time
(C) Weather forecasts do not use measurements
(D) Weather depends only on temperature
Answer: (B) Weather depends on many changing factors and small differences can grow over time
30. What is the main purpose of estimation in scientific thinking?
(A) To obtain an exact value every time
(B) To avoid thinking about quantities
(C) To check whether an answer is reasonable or impossible
(D) To replace scientific measurements permanently
Answer: (C) To check whether an answer is reasonable or impossible
Class 9 Science Chapter 1: Exploration: Entering the World of Secondary Science
Assertion–Reason Questions
Directions: Choose the correct option:
(A) Both Assertion and Reason are true, and Reason is the correct explanation of Assertion.
(B) Both Assertion and Reason are true, but Reason is not the correct explanation of Assertion.
(C) Assertion is true, but Reason is false.
(D) Assertion is false, but Reason is true.
1. Assertion: Scientific models are often simplified representations of real-world situations.
Reason: Models deliberately ignore some details so that important features can be studied more clearly.
Answer: (A)
2. Assertion: Scientific theories are merely guesses made by scientists.
Reason: Scientific theories are based on evidence, careful testing, and critical examination.
Answer: (D)
3. Assertion: Standard units are important in science.
Reason: Standard units allow measurements to be compared consistently and help avoid errors caused by different units.
Answer: (A)
4. Assertion: Scientific predictions are always completely certain, even when they concern the distant future.
Reason: Weather forecasts become less certain as the prediction extends further into the future.
Answer: (D)
5. Assertion: Estimation is useful in scientific thinking.
Reason: Estimation helps check whether an answer is reasonable and can help detect errors.
Answer: (A)
