ATAR Scientific Inquiry & Understanding 2 — Questions and Answers
Question 1: A scientist repeats an experiment five times and gets results that are close together but far from the true value. This describes data that is:
- Accurate but not precise
- Precise but not accurate (Correct answer)
- Both accurate and precise
- Neither accurate nor precise
Correct answer: Precise but not accurate
Precision refers to the consistency of repeated measurements, while accuracy refers to closeness to the true value.
Question 2: When graphing experimental results, placing the independent variable on the x-axis is important because:
- It makes the graph look symmetrical
- The independent variable is the one the experimenter controls and changes (Correct answer)
- The dependent variable is harder to measure
- Convention requires the larger values on the x-axis
Correct answer: The independent variable is the one the experimenter controls and changes
The independent variable is placed on the x-axis because it is the variable the experimenter deliberately manipulates.
Question 3: A student measures the boiling point of water at sea level and obtains 99.4°C instead of 100°C. This error is most likely due to:
- Random error from fluctuating conditions
- Systematic error from an incorrectly calibrated thermometer (Correct answer)
- Parallax error from reading the graph
- Sampling error from using too small a sample
Correct answer: Systematic error from an incorrectly calibrated thermometer
A consistent offset from the true value suggests a systematic error, often caused by faulty or uncalibrated equipment.
Question 4: In a controlled experiment testing the effect of fertilizer on plant growth, which of the following is a controlled variable?
- Amount of fertilizer applied
- Height of plant after 4 weeks
- Amount of water each plant receives (Correct answer)
- Type of fertilizer used
Correct answer: Amount of water each plant receives
Controlled variables are kept constant to ensure only the independent variable affects the results; water amount must remain the same for all plants.
Question 5: A hypothesis must be:
- Proven true before experiments begin
- A testable prediction about the relationship between variables (Correct answer)
- Based solely on mathematical models
- Confirmed by at least three independent studies
Correct answer: A testable prediction about the relationship between variables
A hypothesis is a testable, falsifiable prediction that can be investigated through experimentation.
Question 6: Which action best reduces random error in an experiment?
- Replacing all equipment with new models
- Increasing the number of trials and averaging results (Correct answer)
- Using a control group only
- Changing the independent variable more frequently
Correct answer: Increasing the number of trials and averaging results
Repeating trials and calculating the mean reduces the impact of random fluctuations on results.
Question 7: The peer review process in science primarily serves to:
- Ensure only popular theories are published
- Detect errors and evaluate the validity of research before publication (Correct answer)
- Speed up the publication of new discoveries
- Allow scientists to patent their findings
Correct answer: Detect errors and evaluate the validity of research before publication
Peer review involves expert evaluation of research methodology and conclusions to maintain scientific standards.
ATAR Scientific Inquiry & Understanding 2
A scientist repeats an experiment five times and gets results that are close together but far from the true value.
This describes data that is: