Chapter-1 Exploring the Investigative World of Science — Online MCQ Test
SCIENCE · Grade 8 · CBSE(NCERT)
Practice Chapter-1 Exploring the Investigative World of Science with a free chapter-wise online MCQ test.
This chapter covers: scientific method - hypothesis - variables - observation - data analysis - conclusion.
AI-generated questions from basic to board-exam level, with instant results and explanations.
Chapter-1 Exploring the Investigative World of Science — Important Questions & Answers
What is the first step in the scientific method?
- A. Making a hypothesis
- B. Observation
- C. Drawing conclusions
- D. Analyzing data
Answer: B. Observation
Observation is the initial step where scientists gather information about a phenomenon before forming any hypothesis.
Observation is the initial step where scientists gather information about a phenomenon before forming any hypothesis.
A hypothesis is best defined as:
- A. A proven scientific fact
- B. A testable prediction or proposed explanation
- C. The final result of an experiment
- D. A collection of observations
Answer: B. A testable prediction or proposed explanation
A hypothesis is an educated guess or testable prediction that can be either supported or refuted through experimentation.
A hypothesis is an educated guess or testable prediction that can be either supported or refuted through experimentation.
Which of the following is an example of a variable in an experiment?
- A. The scientific method
- B. Temperature of a substance being tested
- C. The conclusion
- D. A hypothesis
Answer: B. Temperature of a substance being tested
A variable is any factor that can change or be changed during an experiment; temperature is a measurable variable.
A variable is any factor that can change or be changed during an experiment; temperature is a measurable variable.
Data analysis in scientific investigation means:
- A. Making random guesses about results
- B. Organizing and interpreting collected information
- C. Writing the hypothesis
- D. Performing the experiment again
Answer: B. Organizing and interpreting collected information
Data analysis involves examining, organizing, and interpreting the information collected during an experiment to find patterns and meanings.
Data analysis involves examining, organizing, and interpreting the information collected during an experiment to find patterns and meanings.
A student observes that plants grow taller when watered daily compared to watering them weekly. This observation leads to forming a hypothesis. Which of the following would be the most appropriate hypothesis?
- A. Plants are alive
- B. Water is essential for plant growth
- C. Daily watering increases plant height more than weekly watering
- D. All plants need the same amount of water
Answer: C. Daily watering increases plant height more than weekly watering
A good hypothesis is specific, testable, and directly related to the observation made about the relationship between watering frequency and plant height.
A good hypothesis is specific, testable, and directly related to the observation made about the relationship between watering frequency and plant height.
In an experiment testing how temperature affects the speed of a chemical reaction, which variable should be kept constant?
- A. Temperature
- B. The type of chemicals used
- C. The reaction time
- D. The speed of the reaction
Answer: B. The type of chemicals used
The type of chemicals must remain constant so that temperature is the only factor being tested; controlling other variables ensures valid results.
The type of chemicals must remain constant so that temperature is the only factor being tested; controlling other variables ensures valid results.
Consider an experiment where three groups of seedlings receive different amounts of sunlight (2 hours, 4 hours, and 8 hours daily) while all other conditions remain the same. After 30 days, the height of each group is measured. Which of the following is the control group?
- A. The group receiving 2 hours of sunlight
- B. The group receiving 4 hours of sunlight
- C. The group receiving 8 hours of sunlight
- D. None of the groups; a separate group receiving no sunlight would be the control
Answer: D. None of the groups; a separate group receiving no sunlight would be the control
A proper control group receives no treatment or a baseline treatment to serve as a comparison; a group with zero sunlight would show the baseline growth without the variable being tested.
A proper control group receives no treatment or a baseline treatment to serve as a comparison; a group with zero sunlight would show the baseline growth without the variable being tested.
A scientist observes that plants with more nitrogen-rich soil grow faster. Before concluding that nitrogen causes faster growth, what should the scientist do?
- A. Publish the findings immediately
- B. Design an experiment controlling for other variables like water and sunlight
- C. Ask other people what they think
- D. Assume the observation is always true
Answer: B. Design an experiment controlling for other variables like water and sunlight
To confirm causation, other variables must be controlled; the scientist needs to ensure that only nitrogen varies while other factors remain constant.
To confirm causation, other variables must be controlled; the scientist needs to ensure that only nitrogen varies while other factors remain constant.
In a multi-step investigation studying how pH, temperature, and salinity affect the growth of a specific bacterium, a researcher found that temperature had the most significant effect. Which statement BEST explains why additional experiments focusing only on temperature would be important?
- A. To eliminate the need to study pH and salinity
- B. To establish precise relationships and mechanisms for temperature's effect, and to determine optimal temperature ranges for growth
- C. To prove that pH and salinity have no effect whatsoever
- D. To simplify the research and make it easier to publish
Answer: B. To establish precise relationships and mechanisms for temperature's effect, and to determine optimal temperature ranges for growth
Following up on the most significant finding with focused experiments allows deeper understanding of mechanisms, dose-response relationships, and optimal conditions, which is how science builds detailed knowledge.
Following up on the most significant finding with focused experiments allows deeper understanding of mechanisms, dose-response relationships, and optimal conditions, which is how science builds detailed knowledge.
A student finds that an experiment designed to test Hypothesis A actually provides strong support for Hypothesis B instead. The student's advisor suggests publishing this unexpected finding. Why is the advisor's suggestion scientifically sound?
- A. Because any published data is valuable regardless of what it shows
- B. Because unexpected results that are properly documented can advance scientific knowledge and challenge existing assumptions
- C. Because the student should avoid admitting the original hypothesis was wrong
- D. Because Hypothesis B must be more important than Hypothesis A
Answer: B. Because unexpected results that are properly documented can advance scientific knowledge and challenge existing assumptions
Scientific progress often comes from unexpected findings; documenting these rigorously and transparently contributes valuable information to the scientific community and may reveal new phenomena or relationships.
Scientific progress often comes from unexpected findings; documenting these rigorously and transparently contributes valuable information to the scientific community and may reveal new phenomena or relationships.