Sample Quizzes For Preparation: Physical Quantities And Units

AS Level Physics – Topic 1: Physical Quantities and Units

Quiz

Question 1

Which of the following is a vector quantity?
A. Speed
B. Distance
C. Force
D. Time

Question 2

Which of the following is a correct SI base unit?
A. Newton (N)
B. Volt (V)
C. Ampere (A)
D. Pascal (Pa)

Question 3

The derived SI unit for pressure is:
A. kg/m
B. N/m²
C. kg·m/s
D. J/m²

Question 4

Which prefix corresponds to 10⁶?
A. Giga
B. Kilo
C. Mega
D. Tera

Question 5

Which of the following is the correct SI unit for energy?
A. W
B. J
C. Pa
D. V

Question 6

Which of these quantities has both magnitude and direction?
A. Temperature
B. Mass
C. Velocity
D. Distance

Question 7

What is the SI unit for electric current?
A. Coulomb
B. Ampere
C. Volt
D. Ohm

Question 8

Which of the following has units equivalent to kg·m²/s²?
A. Power
B. Force
C. Energy
D. Pressure

Question 9

Which of these is used to represent the prefix ‘micro’?
A. μ
B. m
C. M
D. n

Question 10

A student measures the length of a rod as 3.56 cm ± 0.01 cm. What is the percentage uncertainty?
A. 0.28%
B. 1.12%
C. 2.81%
D. 3.56%

Question 11

The derived SI unit of power is:
A. N
B. J
C. W
D. Pa

Question 12

Which statement about systematic error is true?
A. It causes results to vary randomly
B. It always increases accuracy
C. It shifts results in one direction consistently
D. It has no effect on the mean value

Question 13

What is the dimensional formula for force?
A. M·L·T⁻¹
B. M·L/T
C. M·L/T²
D. M·L²/T²

Question 14

Which of the following quantities is scalar?
A. Displacement
B. Velocity
C. Distance
D. Force

Question 15

How is precision best described?
A. Closeness to true value
B. Degree of consistency in measurements
C. Being error-free
D. Measuring only scalar quantities

Question 16

Which unit is equivalent to a Pascal (Pa)?
A. N·m
B. J/m
C. N/m²
D. W/m²

Question 17

Which of the following represents a correct vector addition condition?
A. Add magnitudes directly
B. Add scalar components only
C. Use graphical or trigonometric methods
D. Always subtract the smaller from the larger

Question 18

The SI unit for frequency is:
A. s
B. Hz
C. rad/s
D. rpm

Question 19

Which is not an SI base unit?
A. metre
B. second
C. mole
D. newton

Question 20

Which prefix means 10⁻⁹?
A. milli
B. micro
C. nano
D. pico

Question 21

What is the correct representation of 3 m/s at 60° to the horizontal in components?
A. 3 cos60°, 3 sin60°
B. 3 sin60°, 3 cos60°
C. 3 tan60°, 3 sin60°
D. 3, 60

Question 22

What does the term ‘homogeneous equation’ mean in physics?
A. All terms have different dimensions
B. All terms are vectors
C. All terms have the same units
D. All terms are equal

Question 23

Which physical quantity has units of m/s²?
A. Velocity
B. Displacement
C. Acceleration
D. Momentum

Question 24

Which of these is true about random errors?
A. They can be eliminated by calibration
B. They result from human mistakes
C. They vary unpredictably
D. They shift values in one direction

Question 25

A 10.0 N force acts horizontally and a 6.0 N force acts vertically. What is the resultant force magnitude?
A. 4.0 N
B. 16.0 N
C. 8.0 N
D. 11.7 N

Question 26

Which SI unit is used for impulse?
A. N·s
B. kg·m
C. m/s
D. J·s

Question 27

Which vector quantity determines direction and rate of change of displacement?
A. Velocity
B. Acceleration
C. Force
D. Speed

Question 28

Why are derived units useful?
A. They simplify measurements
B. They replace base units
C. They represent complex physical relationships
D. They’re used for SI base units

Question 29

Which instrument can be used to measure small lengths with high precision?
A. Ruler
B. Protractor
C. Vernier caliper
D. Spring balance

Question 30

Which is the correct base unit combination for pressure?
A. kg·m/s
B. kg/s²
C. kg/m·s²
D. kg/m²·s²

Answer Key and Explanations

1. C – Force is a vector.
2. C – Ampere is a base unit.
3. B – N/m² is pressure.
4. C – Mega = 10⁶
5. B – Energy is measured in joules (J).
6. C – Velocity has both magnitude and direction.
7. B – SI unit of current is ampere.
8. C – Energy has unit kg·m²/s².
9. A – Micro is represented by μ.
10. A – (0.01 / 3.56) × 100 ≈ 0.28%
11. C – Watt (W) is unit of power.
12. C – Systematic errors shift values consistently.
13. C – Force = mass × acceleration = M·L/T²
14. C – Distance is scalar.
15. B – Precision = repeatability.
16. C – 1 Pa = 1 N/m².
17. C – Vectors must be added graphically or trigonometrically.
18. B – Hz (hertz) = 1/s.
19. D – Newton is derived, not base.
20. C – Nano = 10⁻⁹
21. A – Use cos for horizontal, sin for vertical components.
22. C – Homogeneous = same units throughout.
23. C – Acceleration is m/s².
24. C – Random errors are unpredictable.
25. D – Resultant = √(10² + 6²) = √136 ≈ 11.7 N
26. A – Impulse = Force × time = N·s
27. A – Velocity is rate of change of displacement.
28. C – Derived units express complex relationships.
29. C – Vernier calipers are precise for small lengths.
30. C – Pressure = Force / Area = kg/m·s²