Complete OA Exam Question Bank
200 Exam Questions with Answers and
Rationales
Updated for 2026/2027 Academic Year
SECTION 1: SCIENTIFIC INQUIRY AND METHODOLOGY
(Questions 1-35)
Question 1:
A student notices that a metal spoon left in a hot cup of coffee becomes warm. The
student proposes that heat is transferred from the coffee to the spoon. Which type
of scientific idea is this proposal?
A) Law
B) Theory
C) Hypothesis
D) Observation
Answer: C) Hypothesis
Rationale: A hypothesis is a testable explanation for an observation. The student's
proposal can be tested by measuring temperature changes, so it is a hypothesis. A
law describes patterns, a theory explains broad phenomena, and an observation is a
factual statement.
Question 2:
Which of the following is an example of a scientific law?
A) Objects with mass attract each other
B) The Earth revolves around the Sun because of gravity
,C) Force equals mass times acceleration (F = ma)
D) All living things are made of cells
Answer: C) Force equals mass times acceleration (F = ma)
Rationale: A scientific law is a concise statement, often mathematical, that
describes a fundamental relationship in nature. F=ma is a law. Option A is a broad
principle but not a law; B and D are theories or biological principles.
Question 3:
A conceptual model is BEST described as:
A) A physical replica of an object
B) A set of equations that predict outcomes
C) A verbal, graphical, or diagrammatic explanation of how a system works
D) A statement that has been proven true
Answer: C) A verbal, graphical, or diagrammatic explanation of how a system
works
Rationale: Conceptual models use words, diagrams, or flowcharts to explain
structure or relationships. Physical models are actual objects; mathematical models
use equations.
Question 4:
Which step of the scientific method comes immediately after making an
observation?
A) Formulate a hypothesis
B) Conduct an experiment
C) Ask a question or identify a problem
D) Draw conclusions
Answer: C) Ask a question or identify a problem
Rationale: The typical sequence: observation → question/problem → hypothesis
→ experiment → analyze → conclude. The question arises from the observation.
,Question 5:
A scientist measures the mass of a rock three times and gets 5.2 g, 5.3 g, and 5.1 g.
The true mass is 5.0 g. Which statement best describes these measurements?
A) Accurate but not precise
B) Precise but not accurate
C) Both accurate and precise
D) Neither accurate nor precise
Answer: B) Precise but not accurate
Rationale: The measurements are close to each other (high precision) but not close
to the true value of 5.0 g (low accuracy). Precision refers to reproducibility;
accuracy refers to closeness to the true value.
Question 6:
An independent variable is defined as:
A) The variable that is measured in an experiment
B) The variable that is kept constant
C) The variable that is intentionally changed by the researcher
D) The variable that provides a baseline for comparison
Answer: C) The variable that is intentionally changed by the researcher
Rationale: The independent variable is what the experimenter manipulates or
changes on purpose. The dependent variable is what is measured in response.
Question 7:
Which of the following is a characteristic of a good scientific theory?
A) It is a guess that cannot be tested
B) It is supported by a large body of evidence
C) It is a simple statement of fact
D) It can never be changed
, Answer: B) It is supported by a large body of evidence
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Rationale: A scientific theory is a well-substantiated explanation supported by
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multiple lines of evidence from various experiments and observations.
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Question 8: K.
If a hypothesis is tested and the results do not support it, the scientist should:
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A) Discard the hypothesis immediately K. K. K.
B) Modify or reject the hypothesis and propose a new one
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C) Ignore the results K. K.
D) Publish the results as a theory K. K. K. K. K.
Answer: B) Modify or reject the hypothesis and propose a new one
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Rationale: Science is iterative. If results contradict a hypothesis, the scientist
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should revise it, propose alternatives, or design new experiments, not ignore data.
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Question 9: K.
Which type of model is a mathematical formula like E = mc²?
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A) Conceptual model K.
B) Physical model K.
C) Mathematical model K.
D) Graphical model K.
Answer: C) Mathematical model K. K. K.
Rationale: Mathematical models use equations to represent relationships. E = mc²
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is a mathematical model of mass-energy equivalence.
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Question 10: K.
A control group in an experiment is:
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A) The group that receives the treatment
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B) The group that is not exposed to the independent variable
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