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AQA A LEVEL PHYSICS PAPER 1 EXAM PRACTICE GUIDE AND
CORRECT ANSWERS LATEST EDITION
AQA A Level Physics Paper 1 — Questions with Answers
SECTION 1: Measurements & Their Errors (Questions 1–30)
1. Q: What is the SI base unit of mass?
A: Kilogram (kg).
2. Q: What is the SI base unit of electric current?
A: Ampere (A).
3. Q: Express 3.6 × 10⁶ m in km.
A: 3.6 × 10³ km = 3600 km.
4. Q: What is the prefix for 10⁻⁹?
A: Nano (n).
5. Q: What is the prefix for 10¹²?
A: Tera (T).
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6. Q: Convert 5.0 μC to coulombs.
A: 5.0 × 10⁻⁶ C.
7. Q: Distinguish between systematic and random errors.
A: Systematic errors are consistent, reproducible errors that shift all readings in the same
direction (e.g., zero error). Random errors vary unpredictably and can be reduced by
averaging.
8. Q: What is the difference between accuracy and precision?
A: Accuracy is how close a measurement is to the true value. Precision is how close
repeated measurements are to each other.
9. Q: A length is measured as 25.0 ± 0.5 cm. Calculate the percentage uncertainty.
A: (0.5/25.0) × 100 = 2.0%.
10. Q: A student measures a time of 12.4 s with a stopwatch of resolution 0.1 s. Calculate
the percentage uncertainty.
A: (0.1/12.4) × 100 = 0.81%.
11. Q: How is the uncertainty in a mean value calculated?
A: Uncertainty in the mean = (range of values) / 2, or use the standard deviation.
12. Q: What is the uncertainty when reading a thermometer with 1°C graduations?
A: ±0.5°C (half the smallest division).
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13. Q: Two quantities are added: (5.0 ± 0.2) + (3.0 ± 0.1). What is the absolute uncertainty in
the sum?
A: ±(0.2 + 0.1) = ±0.3.
14. Q: A quantity is calculated as P = VI. If V = 12.0 ± 0.2 V and I = 2.0 ± 0.1 A, calculate P and
its uncertainty.
A: P = 24.0 W. % uncertainty in V = 1.67%, in I = 5%. Total % = 6.67%. Uncertainty = 24.0
× 0.0667 = 1.6 W. So P = 24.0 ± 1.6 W.
15. Q: What is a null measurement?
A: A measurement where the instrument reading is adjusted to zero, eliminating
systematic errors from the scale.
16. Q: What is the purpose of a control variable?
A: A variable kept constant to ensure that changes in the dependent variable are due
only to changes in the independent variable.
17. Q: What is the resolution of an instrument?
A: The smallest change in a quantity that an instrument can detect.
18. Q: Why is a logarithmic graph useful?
A: It can linearise relationships of the form y = axⁿ or y = aeᵏˣ, making it easier to
determine constants.
19. Q: What is the gradient of a graph of y vs x if y = mx + c?
A: The gradient is m.
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20. Q: How do you find the uncertainty in a gradient?
A: Draw maximum and minimum gradient lines and take half the difference.
21. Q: What does the y-intercept of a graph represent physically?
A: It represents the value of the dependent variable when the independent variable is
zero.
22. Q: Convert 0.00045 m to standard form.
A: 4.5 × 10⁻⁴ m.
23. Q: What is the SI unit of force?
A: Newton (N) = kg m s⁻².
24. Q: What is the SI unit of energy?
A: Joule (J) = kg m² s⁻².
25. Q: What is the SI unit of power?
A: Watt (W) = kg m² s⁻³.
26. Q: Show that the units of pressure (Pa) are equivalent to kg m⁻¹ s⁻².
A: Pa = N/m² = (kg m s⁻²)/m² = kg m⁻¹ s⁻².
27. Q: A student measures the diameter of a wire as 0.50 ± 0.01 mm. Calculate the
percentage uncertainty in the cross-sectional area.
A: % uncertainty in diameter = 2%. Area depends on d², so % uncertainty in area = 2 ×
2% = 4%.
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AQA A LEVEL PHYSICS PAPER 1 EXAM PRACTICE GUIDE AND
CORRECT ANSWERS LATEST EDITION
AQA A Level Physics Paper 1 — Questions with Answers
SECTION 1: Measurements & Their Errors (Questions 1–30)
1. Q: What is the SI base unit of mass?
A: Kilogram (kg).
2. Q: What is the SI base unit of electric current?
A: Ampere (A).
3. Q: Express 3.6 × 10⁶ m in km.
A: 3.6 × 10³ km = 3600 km.
4. Q: What is the prefix for 10⁻⁹?
A: Nano (n).
5. Q: What is the prefix for 10¹²?
A: Tera (T).
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,Page 2 of 35
6. Q: Convert 5.0 μC to coulombs.
A: 5.0 × 10⁻⁶ C.
7. Q: Distinguish between systematic and random errors.
A: Systematic errors are consistent, reproducible errors that shift all readings in the same
direction (e.g., zero error). Random errors vary unpredictably and can be reduced by
averaging.
8. Q: What is the difference between accuracy and precision?
A: Accuracy is how close a measurement is to the true value. Precision is how close
repeated measurements are to each other.
9. Q: A length is measured as 25.0 ± 0.5 cm. Calculate the percentage uncertainty.
A: (0.5/25.0) × 100 = 2.0%.
10. Q: A student measures a time of 12.4 s with a stopwatch of resolution 0.1 s. Calculate
the percentage uncertainty.
A: (0.1/12.4) × 100 = 0.81%.
11. Q: How is the uncertainty in a mean value calculated?
A: Uncertainty in the mean = (range of values) / 2, or use the standard deviation.
12. Q: What is the uncertainty when reading a thermometer with 1°C graduations?
A: ±0.5°C (half the smallest division).
2|Page
,Page 3 of 35
13. Q: Two quantities are added: (5.0 ± 0.2) + (3.0 ± 0.1). What is the absolute uncertainty in
the sum?
A: ±(0.2 + 0.1) = ±0.3.
14. Q: A quantity is calculated as P = VI. If V = 12.0 ± 0.2 V and I = 2.0 ± 0.1 A, calculate P and
its uncertainty.
A: P = 24.0 W. % uncertainty in V = 1.67%, in I = 5%. Total % = 6.67%. Uncertainty = 24.0
× 0.0667 = 1.6 W. So P = 24.0 ± 1.6 W.
15. Q: What is a null measurement?
A: A measurement where the instrument reading is adjusted to zero, eliminating
systematic errors from the scale.
16. Q: What is the purpose of a control variable?
A: A variable kept constant to ensure that changes in the dependent variable are due
only to changes in the independent variable.
17. Q: What is the resolution of an instrument?
A: The smallest change in a quantity that an instrument can detect.
18. Q: Why is a logarithmic graph useful?
A: It can linearise relationships of the form y = axⁿ or y = aeᵏˣ, making it easier to
determine constants.
19. Q: What is the gradient of a graph of y vs x if y = mx + c?
A: The gradient is m.
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20. Q: How do you find the uncertainty in a gradient?
A: Draw maximum and minimum gradient lines and take half the difference.
21. Q: What does the y-intercept of a graph represent physically?
A: It represents the value of the dependent variable when the independent variable is
zero.
22. Q: Convert 0.00045 m to standard form.
A: 4.5 × 10⁻⁴ m.
23. Q: What is the SI unit of force?
A: Newton (N) = kg m s⁻².
24. Q: What is the SI unit of energy?
A: Joule (J) = kg m² s⁻².
25. Q: What is the SI unit of power?
A: Watt (W) = kg m² s⁻³.
26. Q: Show that the units of pressure (Pa) are equivalent to kg m⁻¹ s⁻².
A: Pa = N/m² = (kg m s⁻²)/m² = kg m⁻¹ s⁻².
27. Q: A student measures the diameter of a wire as 0.50 ± 0.01 mm. Calculate the
percentage uncertainty in the cross-sectional area.
A: % uncertainty in diameter = 2%. Area depends on d², so % uncertainty in area = 2 ×
2% = 4%.
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