Question 1

1. In an experiment to see how the amount of sunlight affects plant growth, what is the independent variable?

A) The height of the plantB) The amount of sunlightC) The type of soil usedD) The amount of water given

Answer

✓ Correct Answer: Option B

Explanation: The independent variable is the factor changed by the investigator. In this case, the amount of sunlight is deliberately varied.

Question 2

2. A student measures the length of a rod three times and gets 12.1 cm, 12.2 cm, and 12.0 cm. The actual length is 15.0 cm. These measurements are:

A) Accurate and preciseB) Accurate but not precise Precise but not accurate

Question 3

3. Which of the following is a quantitative observation?

A) The liquid has a volume of 250 mLB) The solution turned bright blueC) The gas produced a pungent smellD) The solid felt rough to the touch

Answer

✓ Correct Answer: Option A

Explanation: Quantitative observations involve numerical values and measurements. 250 mL is a specific quantity.

Question 4

4. If a car travels a distance d = 100m in time t = 5 s, what is its speed v using the formula $v = \frac{d}{t}$?

A) 500 m/sB) 0.05 m/sC) 20 m/sD) 105 m/s

Answer

✓ Correct Answer: Option C

Question 5

5. What is the purpose of a 'control' in a scientific investigation?

A) To make the experiment run fasterB) To provide a standard for comparisonC) To change multiple variables at onceD) To ensure the result is always positive

Answer

✓ Correct Answer: Option B

Explanation: A control is used to ensure that the observed effect is actually caused by the independent variable being tested.

Question 6

6. A student measures the mass of an object as 45.2g, 45.4g, 45.3g. Calculate the mean mass.

A) 45.2 gB) 45.4 gC) 135.9 gD) 45.3 g

Answer

✓ Correct Answer: Option D

Explanation: $$Mean = \frac{45.2 + 45.4 + 45.3}{3} = \frac{135.9}{3} = 45.3g$$

Question 7

7. On which axis of a graph should the independent variable usually be plotted?

A) The x-axis (horizontal)B) The y-axis (vertical)C) The z-axisD) The diagonal axis

Answer

✓ Correct Answer: Option A

Explanation: Conventionally, the independent variable (cause) is on the x-axis and the dependent variable (effect) is on the y-axis.

Question 8

8. Convert 1.5 kilometers into meters.

A) 15 mB) 150 mC) 1500 mD) 15000 m

Answer

✓ Correct Answer: Option C

Question 9

9. Which of these is a properly written scientific hypothesis?

A) I think plants like water.B) If the temperature increases, then the rate of reaction will increase.C) Why do birds fly south?D) The experiment was successful.

Answer

✓ Correct Answer: Option B

Explanation: A hypothesis should be a testable statement, often in the "If... then..." format.

Question 10

10. An error that occurs when a weighing scale is not set to zero before use is called:

A) Random errorB) Human errorC) Rounding errorD) Systematic error

Answer

✓ Correct Answer: Option D

Explanation: A systematic error (like a zero error) shifts all measurements by the same amount in the same direction.

Question 11

11. Calculate the percentage error if the experimental value is 9.0 and the theoretical value is 10.0.

A) 10%B) 1%C) 90%D) 11.1%

Answer

✓ Correct Answer: Option A

Explanation: $$% error = \frac{|10.0 - 9.0|}{10.0} \times 100 = \frac{1.0}{10.0} \times 100 = 10%$$

Question 12

12. What is the SI unit of thermodynamic temperature?

A) Celsius ($^\circ C$)B) Fahrenheit ($^\circ F$)C) Kelvin (K)D) Joule (J)

Answer

✓ Correct Answer: Option C

Question 13

13. If you have a dataset: 5, 8, 12, 15, 20. What is the range?

A) 12B) 15C) 20D) 5

Answer

✓ Correct Answer: Option B

Question 14

14. A scientist wants to measure the volume of an irregular stone. Which method should they use?

A) Length $\times$ Width $\times$ HeightB) Weighing it on a balanceC) Water displacement in a graduated cylinderD) Using a ruler to measure the diameter

Answer

✓ Correct Answer: Option C

Explanation: Water displacement measures the volume of irregular objects by observing the change in water level.

Question 15

15. Write 0.00045 in scientific notation.

A) $4.5 \times 10^{-4}$B) $4.5 \times 10^4$C) $45 \times 10^{-5}$D) $0.45 \times 10^{-3}$

Answer

✓ Correct Answer: Option A

Explanation: Move the decimal 4 places to the right: $4.5 \times 10^{-4}$.

Question 16

16. To increase the reliability of an experiment, a scientist should:

A) Change two variables at onceB) Repeat the experiment multiple timesC) Use a larger font in the reportD) Only record the results they like

Answer

✓ Correct Answer: Option B

Explanation: Repetition and averaging results help reduce the impact of random errors and increase reliability.

Question 17

17. Which piece of equipment is most precise for measuring 12.5 mL of liquid?

A) 100 mL BeakerB) 250 mL Erlenmeyer flaskC) 500 mL Plastic jugD) 25 mL Graduated cylinder

Answer

✓ Correct Answer: Option D

Explanation: A smaller graduated cylinder has finer markings (increments), making it more precise for small volumes.

Question 18

18. If a line on a distance-time graph is a straight horizontal line, it means the object is:

A) Stationary (at rest)B) Moving at a constant speedC) AcceleratingD) Decelerating

Answer

✓ Correct Answer: Option A

Explanation: A horizontal line means the distance is not changing as time passes, so speed is zero.

Question 19

19. In the formula for density $\rho = \frac{m}{V}$, if mass m = 50g and volume $V = 10cm^3$, what is \rho?

A) $0.2 g/cm^3$B) $500 g/cm^3$C) $5 g/cm^3$D) $60 g/cm^3$

Answer

✓ Correct Answer: Option C

Question 20

20. An 'inference' is:

A) Directly seeing something with your eyesB) A logical explanation based on observationsC) A guess made without any evidenceD) The final measurement in an experiment

Answer

✓ Correct Answer: Option B

Explanation: Inferences go beyond the literal observation to provide a possible explanation for what was seen.

Accepted Answer

✓ Correct Answer: Option C

Explanation: The measurements are close to each other (precise) but far from the true value of 15.0 cm (not accurate).

Grade 8 : Science (Curiosity) - Investigative Science (Set 1)

1. In an experiment to see how the amount of sunlight affects plant growth, what is the independent variable?

2. A student measures the length of a rod three times and gets 12.1 cm, 12.2 cm, and 12.0 cm. The actual length is 15.0 cm. These measurements are:

3. Which of the following is a quantitative observation?

4. If a car travels a distance d = 100m in time t = 5 s, what is its speed v using the formula $v = \frac{d}{t}$?

5. What is the purpose of a 'control' in a scientific investigation?

6. A student measures the mass of an object as 45.2g, 45.4g, 45.3g. Calculate the mean mass.

7. On which axis of a graph should the independent variable usually be plotted?

8. Convert 1.5 kilometers into meters.

9. Which of these is a properly written scientific hypothesis?

10. An error that occurs when a weighing scale is not set to zero before use is called:

11. Calculate the percentage error if the experimental value is 9.0 and the theoretical value is 10.0.

12. What is the SI unit of thermodynamic temperature?

13. If you have a dataset: 5, 8, 12, 15, 20. What is the range?

14. A scientist wants to measure the volume of an irregular stone. Which method should they use?

15. Write 0.00045 in scientific notation.

16. To increase the reliability of an experiment, a scientist should:

17. Which piece of equipment is most precise for measuring 12.5 mL of liquid?

18. If a line on a distance-time graph is a straight horizontal line, it means the object is:

19. In the formula for density $\rho = \frac{m}{V}$, if mass m = 50g and volume $V = 10cm^3$, what is \rho?

20. An 'inference' is: