The Wonderful World of Science Part 2: MCQs (Q26–Q50)
Part 2 — Questions 26–50
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The basic quality of a good scientific measurement is that it should be:
A. Always odd.
B. Accurate and precise. ← Correct answer: B
C. Made without units.
D. Only estimated.
Explanations:
A/C/D) Incorrect.
B) Correct — accuracy (close to true value) and precision (repeatable) are key. -
Which is NOT an example of a scientific tool?
A. Thermometer.
B. Microscope.
C. Comic book. ← Correct answer: C
D. Measuring tape.
Explanations:
A/B/D) Tools used for measurements/observations — incorrect choice.
C) Correct — comic books are not scientific instruments (though educational). -
The SI base unit for length is:
A. Gram.
B. Metre. ← Correct answer: B
C. Second.
D. Litre.
Explanations:
A) Gram = mass.
B) Correct — metre is unit of length.
C) Second = time.
D) Litre = volume (not SI base but commonly used). -
A beaker with markings is mainly used to:
A. Measure exact mass.
B. Estimate liquid volumes roughly. ← Correct answer: B
C. Measure temperature.
D. Measure time.
Explanations:
A/C/D) Incorrect.
B) Correct — beakers are for holding and approximate volume readings; for accurate volume use graduated cylinder or pipette. -
Which of the following shows careful qualitative observation?
A. “The liquid tastes awful.”
B. “The solution turned blue after adding the reagent.” ← Correct answer: B
C. “It’s nice.”
D. “5 grams.”
Explanations:
A/C) Subjective or unsafe (tasting) — incorrect.
B) Correct — describes a visible change objectively.
D) Quantitative, not qualitative. -
If two measurements give values 10.2 cm and 10.3 cm, these measurements are:
A. Inconsistent.
B. Precise (similar values). ← Correct answer: B
C. Useless.
D. Differing by a large amount.
Explanations:
A/C/D) Incorrect.
B) Correct — closeness indicates precision. -
Which is an example of a controlled variable when testing how sunlight affects plant growth?
A. Amount of sunlight (changed).
B. Type of soil (kept the same). ← Correct answer: B
C. Plant height at end (dependent).
D. Random weather changes.
Explanations:
A) Independent variable.
B) Correct — keep soil same to isolate sunlight effect.
C) Dependent variable.
D) Uncontrolled factors reduce experiment quality. -
Calibration of an instrument means:
A. Breaking it.
B. Checking and adjusting it against a known standard. ← Correct answer: B
C. Painting it red.
D. Hiding it.
Explanations:
A/C/D) Incorrect.
B) Correct — ensures accurate measurements. -
Which action improves reliability of results?
A. Using fewer data points.
B. Repeating the experiment multiple times. ← Correct answer: B
C. Ignoring negative results.
D. Changing units randomly.
Explanations:
A/C/D) Incorrect.
B) Correct — repetition increases confidence. -
Which of the following should you do if an experiment produces unexpected results?
A. Hide them.
B. Check the procedure, repeat the test and report honestly. ← Correct answer: B
C. Invent new data to match hypothesis.
D. Stop science altogether.
Explanations:
A/C/D) Unethical or absurd.
B) Correct — investigate possible errors, repeat, accept results. -
An ecosystem model in the classroom is an example of:
A. Scientific law.
B. A physical or conceptual model to explain relationships. ← Correct answer: B
C. Measurement device.
D. A scientific journal.
Explanations:
A/C/D) Incorrect.
B) Correct — models represent interactions among living/nonliving parts. -
Which of the following is an example of secondary source of scientific information?
A. Original experiment notes.
B. A textbook summarizing many experiments. ← Correct answer: B
C. Lab raw data file.
D. A lab notebook.
Explanations:
A/C/D) Primary sources (original data).
B) Correct — textbook interprets and compiles primary sources. -
Which practice is part of ethical science?
A. Fabricating data.
B. Acknowledging the work of others (citations). ← Correct answer: B
C. Plagiarism.
D. Misleading readers intentionally.
Explanations:
A/C/D) Unethical.
B) Correct — crediting others is ethical. -
Which instrument measures very small lengths precisely (to fractions of a millimetre)?
A. Stopwatch.
B. Vernier caliper. ← Correct answer: B
C. Thermometer.
D. Graduated cylinder.
Explanations:
A/C/D) Not for small length precision.
B) Correct — vernier calipers measure internal/external dimensions accurately. -
When designing a fair test, you must:
A. Change several variables at once.
B. Change only one independent variable at a time. ← Correct answer: B
C. Use different measurement units each trial.
D. Never record data.
Explanations:
A/C/D) Incorrect.
B) Correct — isolates cause-effect relationship. -
The process of checking whether a result is repeatable by others is called:
A. Experimentation.
B. Verification or replication. ← Correct answer: B
C. Guessing.
D. Ignorance.
Explanations:
A) Broader term.
B) Correct — replication by independent researchers strengthens findings.
C/D) Incorrect. -
Which of the following is TRUE about scientific laws?
A. They are guesses without evidence.
B. They describe observed regularities and patterns (often expressed mathematically). ← Correct answer: B
C. They cannot be tested.
D. They always explain why phenomena occur.
Explanations:
A/C) Incorrect.
B) Correct — laws summarize consistent observations (e.g., gravity laws).
D) Often laws describe what happens; theories explain why. -
Which is a benefit of science in daily life?
A. Making things more dangerous.
B. Providing medicines, improved agriculture, communication devices. ← Correct answer: B
C. Removing curiosity.
D. Preventing cooking.
Explanations:
A/C/D) Incorrect/absurd.
B) Correct — science leads to practical improvements. -
An example of qualitative data about a plant is:
A. 12 cm height.
B. Leaves are dark green and glossy. ← Correct answer: B
C. Weight = 30 g.
D. Volume = 50 mL.
Explanations:
A/C/D) Quantitative.
B) Correct — descriptive (qualitative). -
Which one of these is a correct reason to use scientific names for organisms?
A. They are easier to remember than common names.
B. They avoid confusion by providing a unique international name. ← Correct answer: B
C. They are only used in fiction.
D. They change every day.
Explanations:
A/C/D) Incorrect.
B) Correct — binomial nomenclature gives a standard name worldwide. -
A good scientific question is one that is:
A. Vague and untestable.
B. Specific and testable by observation or experiment. ← Correct answer: B
C. Based only on belief.
D. Impossible to check.
Explanations:
A/C/D) Incorrect.
B) Correct — testability distinguishes scientific questions. -
Why is it important to record the conditions (like temperature) during an experiment?
A. To confuse readers.
B. Because conditions can affect results and must be known for replication. ← Correct answer: B
C. Conditions never change outcomes.
D. To make the experiment secret.
Explanations:
A/C/D) Incorrect.
B) Correct — documenting conditions helps others reproduce experiments. -
Which of the following is an example of a scientific activity for kids?
A. Copying text without understanding.
B. Observing plant growth under different light and noting results. ← Correct answer: B
C. Guessing answers randomly.
D. Refusing to ask questions.
Explanations:
A/C/D) Not scientific approaches.
B) Correct — simple experiments promote learning. -
Reliability of a measuring instrument is improved by:
A. Ignoring calibration.
B. Regular calibration and careful handling. ← Correct answer: B
C. Dropping it often.
D. Using broken parts.
Explanations:
A/C/D) Incorrect.
B) Correct — calibration and care ensure consistent readings. -
Which scientific attitude helps a student try again after a failed experiment?
A. Laziness.
B. Persistence and curiosity. ← Correct answer: B
C. Dishonesty.
D. Avoidance.
Explanations:
A/C/D) Negative traits — incorrect.
B) Correct — persistence leads to learning and improvement.