Physical Quantities And Measurement TechniquesCopy
MULTIPLE CHOICE QUESTIONS
Q1. Which of the following represents a derived unit in terms of base SI units?
A. Kilogram
B. Metre
C. Second
D. Newton
Q2. A micrometer screw gauge gives a reading of 6.00 mm. If its zero error is –0.03 mm, what is the corrected length?
A. 5.97 mm
B. 6.03 mm
C. 6.30 mm
D. 5.70 mm
Q3. Which of the following prefixes represents the smallest value?
A. micro
B. milli
C. nano
D. pico
Q4. In an experiment, a student records multiple values for time, all close to each other but far from the actual value. This indicates:
A. High accuracy and low precision
B. Low accuracy and high precision
C. High accuracy and high precision
D. Low accuracy and low precision
Q5. Which of the following is not a scalar quantity?
A. Energy
B. Distance
C. Force
D. Time
Q6. A vernier caliper has a main scale reading of 3.4 cm and a vernier scale reading of 0.06 cm. What is the total length?
A. 3.46 cm
B. 3.40 cm
C. 3.06 cm
D. 3.60 cm
Q7. Which of the following is a base quantity in the SI system?
A. Volume
B. Temperature
C. Force
D. Speed
Q8. Which measurement has the most significant figures?
A. 0.0070
B. 3.000
C. 0.30
D. 1.0040
Q9. The unit of pressure (Pascal) is equivalent to:
A. kg/m
B. N/m²
C. N·m
D. kg·m/s²
Q10. Which of the following best reduces parallax error in measurement?
A. Using opaque instruments
B. Viewing at an angle
C. Viewing scale perpendicularly
D. Using bright lights
Q11. What is the main cause of systematic error?
A. Careless observations
B. Faulty equipment
C. Human reaction time
D. Varying environmental conditions
Q12. Which value is closest to the order of magnitude of the diameter of a human hair?
A. 10⁻¹ m
B. 10⁻³ m
C. 10⁻⁶ m
D. 10⁻⁹ m
Q13. What is the uncertainty in a digital stopwatch displaying time as 12.53 s?
A. ±0.1 s
B. ±0.01 s
C. ±1 s
D. ±0.001 s
Q14. Which device gives the highest precision in measuring small lengths?
A. Ruler
B. Measuring tape
C. Vernier caliper
D. Micrometer screw gauge
Q15. Two quantities have units m² and m/s respectively. What is the unit of their product?
A. m³/s
B. m²/s
C. m³
D. m/s²
Q16. Which of these is the correct definition of a second based on SI?
A. Duration of one Earth rotation
B. Average time between heartbeats
C. Based on Cesium atom transitions
D. Time to boil 1g of water
Q17. Which of the following quantities is dimensionless?
A. Speed
B. Angle in radians
C. Mass
D. Force
Q18. A measurement of 2.740 m has how many significant figures?
A. 2
B. 3
C. 4
D. 5
Q19. Which error is not reduced by taking repeated measurements?
A. Systematic error
B. Random error
C. Zero error
D. Parallax error
Q20. Which pair of units is mismatched?
A. Force – Newton
B. Pressure – Pascal
C. Energy – Joule
D. Power – Volt
Q21. Which of these instruments can most accurately measure internal diameter of a test tube?
A. Ruler
B. Micrometer
C. Vernier caliper
D. Stopwatch
Q22. A measuring tape has a smallest division of 1 mm. What is the absolute uncertainty in a single measurement?
A. ±1 mm
B. ±0.5 mm
C. ±0.1 mm
D. ±5 mm
Q23. What does the gradient of a displacement-time graph represent?
A. Speed
B. Acceleration
C. Force
D. Displacement
Q24. The least count of a vernier caliper is:
A. 0.1 mm
B. 0.01 mm
C. 0.01 cm
D. 1 mm
Q25. Why should you avoid parallax error?
A. It speeds up reading
B. It leads to systematic over/underestimations
C. It improves zero error
D. It allows estimation of volume
Q26. Which of these graphs would represent uniform acceleration?
A. Linear displacement-time graph
B. Curved velocity-time graph
C. Straight velocity-time graph
D. Horizontal acceleration-time graph
Q27. Which of the following is true about the SI system?
A. SI units are only used in Europe
B. It’s not internationally accepted
C. It includes base and derived units
D. There is no unit for temperature
Q28. Which is a correct order of magnitude estimate for human walking speed?
A. 10⁻¹ m/s
B. 10⁰ m/s
C. 10¹ m/s
D. 10² m/s
Q29. If you divide a force by area, what do you obtain?
A. Work
B. Power
C. Acceleration
D. Pressure
Q30. The SI unit for energy is defined as:
A. kg·m/s²
B. N·m
C. kg·m/s
D. m²/s²
Q31. The ratio of distance to time is:
A. Speed
B. Acceleration
C. Force
D. Work
Q32. What unit results when you multiply power and time?
A. Watt
B. Joule
C. Newton
D. Pascal
Q33. A reading taken with a stopwatch shows inconsistent timing values. What is most likely the source of error?
A. Zero error
B. Parallax error
C. Reaction time
D. Calibration error
Q34. Which measurement is most precise?
A. 4.6 cm
B. 4.60 cm
C. 4.600 cm
D. 4.6000 cm
Q35. What is the role of estimation in experimental physics?
A. To guarantee accuracy
B. To eliminate human error
C. To provide a rough initial value
D. To replace real measurement
Written and Compiled By Sir Hunain Zia, World Record Holder With 154 Total A Grades, 7 Distinctions and 11 World Records For Educate A Change O Level And IGCSE Physics Full Scale Course
MARKING KEY WITH EXPLANATIONS
| Q | Correct | Explanation |
|---|---|---|
| 1 | D | Newton is a derived unit (kg·m/s²); others are base. |
| 2 | A | Correction = 6.00 – 0.03 = 5.97 mm. |
| 3 | D | pico = 10⁻¹², smallest among options. |
| 4 | B | Values close to each other = high precision, but far from actual = low accuracy. |
| 5 | C | Force is a vector quantity. Others are scalars. |
| 6 | A | Total = 3.4 + 0.06 = 3.46 cm. |
| 7 | B | Temperature (Kelvin) is an SI base quantity. |
| 8 | D | 1.0040 has 5 significant figures. |
| 9 | B | Pressure = Force / Area = N/m². |
| 10 | C | Always view scales perpendicularly to reduce parallax. |
| 11 | B | Faulty equipment causes systematic error. |
| 12 | B | Hair ~ 10⁻³ m (about 0.1 mm). |
| 13 | B | Digital devices have uncertainty ±1 least digit = ±0.01 s. |
| 14 | D | Micrometer is most precise for tiny lengths. |
| 15 | A | m² × m/s = m³/s. |
| 16 | C | Second is defined by Cesium atomic transitions. |
| 17 | B | Radian is dimensionless (ratio of arc to radius). |
| 18 | C | 2.740 has 4 sig figs. |
| 19 | A | Systematic errors persist even in repeated measures. |
| 20 | D | Volt is unit of potential difference, not power. Power is watt. |
| 21 | C | Vernier caliper measures internal/external dimensions. |
| 22 | B | Uncertainty = ±0.5 of smallest division = ±0.5 mm. |
| 23 | A | Gradient of displacement-time = speed. |
| 24 | C | Least count of vernier caliper = 0.01 cm. |
| 25 | B | Parallax causes consistent over/under readings. |
| 26 | C | Constant acceleration gives straight velocity-time graph. |
| 27 | C | SI system includes both base and derived units. |
| 28 | B | Average walking speed ≈ 1 m/s = 10⁰ m/s. |
| 29 | D | Pressure = Force/Area. |
| 30 | B | Joule = N·m. |
| 31 | A | Speed = distance / time. |
| 32 | B | Power × time = energy = joule. |
| 33 | C | Reaction time affects manual stopwatch readings. |
| 34 | D | More decimal places = more precision. |
| 35 | C | Estimation provides rough guidance before real measurement. |